Class X Science Support Material

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KENDRIYA VIDYALAYA SANGATHAN
SUPPORT MATERIAL FOR CLASS X
SUBJECT - SCIENCE
[SESSION-2015-2016]
PATNA REGION
KENDRIYA VIDYALAYA
SANGATHAN
Patna Region

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STUDY MATERIAL
2015-16
CLASS X
SCIENCE

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PREFACE
Kendriya Vidyalaya is a pioneer organization which caters to the all round round
development of the students. Time to time various strategies have been adopted to adorn the
students with academic excellence. Keeping in view of the implementation of CCE it is desired
to prepare study/ support material for Class IX to guide the students in the right direction and
to equip the students to face the challenges with ease.
This support material is one such effort by Kendriya Vidyalaya Sangathan, an empirical
endeavor to help students learn more effectively and efficiently. It is designed to give proper
platform to students for better practice and understanding of the chapters. This can suitably be
used during revision. Ample opportunity has been provided to students through master cards
and question banks to expose them to the CBSE pattern. It is also suggested to students to
keep in consideration the time-management aspect as well.
I extend my heartiest gratitude to the Kendriya Vidyalaya Sangathan authorities for
providing the support material to the students prepared by various Regions. The same has
been reviewed by the Regional Subject Committee of Patna Region who have worked
arduously to bring out the best for the students. I also convey my regards to the staff of
Regional Office, Patna for their genuine cooperation.
In the end, I earnestly hop that this material will not only improve the academic result of
the students but also inculcate learning habit in them.
M.S. Chauhan
Deputy Commissioner

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INDEX
Support Material for Class X
UNIT 1: Chemical Substances
1. Chapter 1. Chemical Reactions and Equations 9
2. Chapter 2. Acids, Bases and Salts 16
3. Chapter 3. Metals and Non-Metals 25
UNIT 2: World of Living
1. Chapter 6. Life Processes 34
2. Chapter 7. Control and Coordination 46
UNIT 3: Effects of Current
1. Chapter 12. Electricity 57
2. Chapter 13. Magnetic Effects of Electric Current 64
UNIT 4: Natural Resources
1. Chapter 14. Source of Energy 71

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SUPPORT MATERIAL
CLASS-X (SCIENCE)
FIRST TERM
2014-15
HOW TO USE SUPPORT MATERIAL
1. This support material is not the substitute of NCERT Text book.
2. At first go through the text book chapter wise to develop a basic concept of the
various topics of the chapter.
3. Study support material topic wise relating it with the text book to develop
lateral thinking.
4. Give more attention on the table, charts and diagrams given in the study
material.
5. Refresh your concept with mind map given for every chapter.
6. First practice the solve question paper of support material.
7. Try to find solutions of unsolved questions given for practice.
8. Practice the CBSE sample papers to clear your concept more and more to the
topic concerned.
9. Make a group of 4 to 5 student to solve HOT questions and Value based
questions.
10. In case of any difficulty in understanding the topic take the help of concern
subject teacher.
****************

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TERM I
CHAPTER- 1
CHEMICAL REACTIONS AND EQUATIONS
GIST OF THE LESSON
1)Chemical reaction— Chemical changes or chemical reactions are the changes in
which one or more new substances are formed.
2)Chemical Equations – Representation of a chemical reaction in terms of symbols and
formulae of the reactants and products is known as chemical equation.
3)Balanced Chemical equations – The chemical equation in which the no. of atoms of different elements is
same on both sides of the arrow is called balanced chemical equation.
It obeys the law of conservation of mass and helpful in stoichiometric calculation.
4) The chemical reactions can be classified into different types such as—
a) Combination reaction – The reactions in which two or more substances combine to form a new
substance are called combination reaction. For example,
2Mg(s) + O2 (g)  2 MgO (s)
b) Decomposition reaction - The reaction in which a single compound breaks up into two or more
simpler substances are called decomposition reactions. For example,
The decomposition of a substance by passing electric current through it is known as electrolysis
(Electrical Decomposition).
2H2O 2H2(g) + O2(g)
The decomposition of a substance on heating is known as thermal decomposition.
2Pb (NO3)2 (s)  2PbO (s) + 4NO2 (g) +O2 (g)
2FeSO4 Fe2O3 (s) + SO2(g) +SO3(g)
CaCO3 CaO (s) + CO2(g)
The decomposition of a substance by absorbing light energy is called photochemical decomposition.
2AgBr(s) 2Ag (s) + Br2 (g)
c) Displacement reactions -The chemical reactions in which a more reactive element displaces a less
reactive element from a compound are known as displacement reactions. For example,
i) Zn (s) + CuSO4 (aq)  ZnSO4 (aq) + Cu (s).
Blue solution colourless solution red ppt.
ii) Cu (s) + 2AgNO3 (aq)  Cu (NO3)2 (aq) + 2Ag (s).
Colourless green solution black ppt.
d) Double Displacement Reactions - The chemical reactions in which compounds react to form two
different compounds by mutual exchange of ions are called double displacement reactions.
These reactions take place in solution two common types of this reaction are precipitation reactions
and neutralization reactions
i) Precipitation reaction : In this reactions, aqueous solution of two salts are mixed where some salts
precipitate due to mutual exchange of ions between the two salts. For example
AgNO3 (aq) + NaCI (aq) -----> AgCl(s) + NaNO3.
Curdy white ppt
BaCl2 (aq) + Na2SO4(aq) BaSO4(s) + 2NaCl(aq)
White ppt.
ii) Neutralization reaction: In this type of reaction an acid reacts with a base to form salt and water
by exchange of ions.
NaOH (aq) + HCl (aq)  NaCl (aq) + H2O.

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e) Redox reaction: Chemical reaction which shows both oxidation and reduction reaction.
Oxidation: Reaction that involves the gain of oxygen or loss of hydrogen.
Reduction: Reaction that shows the loss of oxygen or gain of hydrogen.
Both oxidation and reduction take place simultaneously and hence called redox reaction.
ZnO + C  Zn +CO
ZnO reduce to Zn ---- reduction
C oxidize to CO ------oxidation
MnO2 + 4HCl MnCl2 + 2H2O + Cl2.
HCl oxidised to Cl2 whereas MnO2 is reduced to MnCl2
f) Exothermic reaction and endothermic reaction: On the basis of energy changes during chemical reaction,
they can be classified as
i)Exothermic reaction: A chemical reaction in which heat energy is produced.
C + O2 CO2 (g) + heat
ii) Endothermic reaction: A chemical reaction in which heat energy is absorbed.
CaCO3(s) + Heat  CaO(s) + CO2(g)
5 Corrosion – The process of slow conversion of metals into their undesirable compounds due to their reaction
with oxygen, water, acids, gases etc. present in the atmosphere is called corrosion.
Rusting – Iron when reacts with oxygen and moisture forms red substance called rust. Chemical composition of
rust is Fe2O3.xH2O. Its chemical name is Hydrated Iron (III) oxide.
6 Rancidity – The taste and odour of food materials containing fat and oil changes when they are left exposed to
air for long time. This is called rancidity. It is caused due to oxidation of fat and oil present in food material.
It can be prevented by using various methods such as
 by adding antioxidants to the food materials.
 By refrigeration
 Storing food in air tight container and
 by flushing out air with nitrogen.

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MIND MAP
TYPE OF CHEMICAL
REACTIONS
Decomposition
Reaction
EXOTHERMIC-Release heat
ENDOTHERMIC-Absorb heat
REDOX REACTION
Shows both Oxidation and
Reduction
COMBINATION
Two or more
substance
combined to
give single
product
A + B  C
DECOMPOSITION
Single substances
decomposes to
give two or more
new substances
A  B + C
DISPLACEMENT
More reactive
element displaces
less reactive
element
A + BC  AC + B
DOUBLE
DISPLACEMENT
Two different
atoms or group
of atoms
displaces each
Other
AB+CD->AC+BD
RANCIDITY
Oxidation of
fats and oil
CORROSION
Eating away
of metals
CHEMICAL
EQUATION
WRITING BALANCING

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CHEMICAL REACTIONS AND EQUATIONS
PRACTICE QUESTIONS FOR FORMATIVE ASSESSMENT I
Q. PAPER
MARKS-30 TIME- 70 MINUTES
Instructions:
 Questions : 1 to 5 – 1 Mark each
 Questions : 6 to 9 – 2 Marks each
 Question 14 – 5 Marks
1. On what chemical law, balancing of chemical equation is based?
2. Identify the compound oxidized in the following reaction:
2PbO (s) +C (s)  Pb(s) + CO2(g)
3. Give an example of photochemical reaction.
4. Name the reaction which forms insoluble salts.
5. Name the product obtained and type of reaction given below:
Na2SO4 + BaCl2 _________ + ________
6. Explain the following in terms of gain or loss of oxygen with one example:
a. Oxidation
b. Reduction
7. A copper coin is kept in a solution of silver nitrate for some time, what will happen to the coin and the
colour of the solution?
8. Why do we apply paint on iron articles?
9. What happens chemically when quicklime is added to water?
10. What is rancidity? Write the common methods to prevent it.
11. What is corrosion? State the conditions necessary for rusting of iron. How rusting is harmful?
12. Name the type of reactions in the following cases:
a. Garbage producing foul smell
b. Burning of natural gas.
c. Carbon dioxide gas passed through lime water.
13. Oil and fat containing food items are flushed with nitrogen. Whyt?
14.
a. Why can not a chemical change be normally reversed?
b. Why is it always essential to balance a chemical equation?
c. What happens when CO2 gas is passed through lime water and why does it disappear on passing
excess CO2?
d. Can rusting of iron take place in distilled water?
HOTS QUESTIONS (SOLVED)
Q.1. A water insoluble substance ‘X’ on reacting with dilute H2SO4 released a colourless and odourless gas
accompanied by brisk effervescence. When the gas was passed through water, the solution obtained
turned blue litmus red. On bubbling the gas through lime water, it initially became milky and
milkiness disappeared when the gas was passed in excess. Identify the substance ‘X’. Write its

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chemical equations of the reactions involved.
Ans. The water insoluble substance ‘X’ is metal carbonate CaCO3.
CaCO3 (s) + H2SO4 (aq)  CaSO4(Aq) + H2O (Aq) + CO2 (G)
Ca(OH)2 + CO2 (G)CaCO3 (S) + H2O (L)
(milky)
CaCO3 (S) + CO2 (G)+ H2O (Aq)Ca(HCO3)2
(milkiness disappeared)
Q.2. Ahmad took a magnesium ribbon (cleaned) and burned it on a flame. The white powder formed was
taken in a test tube and water was added to it. He then tested the solution formed with red and blue
litmus paper. What change was seen? Why?
Ans. Red litmus paper turned blue.
Blue litmus paper remained blue.
This is because the magnesium ribbon on burning in air forms the white magnesium oxide.
Which dissolved in water, it forms magnesium hydroxide, which is Basic in nature.
Q.3. A solution of a substance ‘X’ is used for white washing.
(a) Name the substance ‘X’ and write its formula.
(b) Write the reaction of the substance ‘X’ named on (a) above with water.
Q.4. Marble statues often slowly get corroded when kept in open for a long time. Assign a suitable
explanation.
Q.5. Mohan took pure water for the electrolytic decomposition of water but did not see any bubbles near
the electrodes. Explain why?
Q. 6 A white salt on heating decomposes to give brown fumes and yellow residue is left behind. Name the
salt and write the reaction involved.
Q. 7 A substance ‘X’ displaces ‘Y’ from its solution in water. It is called displacement reaction. What other
chemical name can be given to such type of reactions? Explain, giving an example?
Q. 8 A grey coloured metal ‘Z’ (Atomic weight=65) is used in making dry cell. It reacts with dil. HCl to
liberate a gas. What is the gas evolved? Calculate the minimum amount of ‘Z’ required to produce
100 litre of gas?
Q. 9 Why respiration is considered an exothermic reaction and photosynthesis is considered an
endothermic reaction ? Explain
Q. 10 Translate the following statement into chemical equation and then balance the equation:
(a) Phosphorous burn in oxygen to give phosphorous pentaoxide
(b) Aluminium metal displace iron from ferric oxide Fe2O3 giving aluminium oxide and iron.
(c) Carbon disulphide burn in air to give carbon dioxide and sulphur dioxide.
(d) Barium chloride reacts with zinc sulphate to give zinc chloride and barium sulphate.
Q. 11 Why decomposition reactions are called opposite of combination reactions? Write equations for
these reactions.

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Q. 12 A shiny brown coloured element ‘X’ on heating in air becomes a black coloured compound. Name
the element ‘X’& black the coloured compound formed. Also write the equation.
FA II
CHEMICAL REACTION AND EQUATIONS
Oral questions (Conversation type)
1. a) How do you represent chemical changes in chemistry?
b) What should you know to write a chemical equation?
c) How are reactants and products separated in a chemical equation?
2. a) Is it essential to write balanced chemical equation?
b) What will happen if it is not balance?
c) How do you know that the equation is not balance?
3. a) What happens when calcium carbonate is heated?
b) What is this reaction called?
c) Does decomposition take place only on heating?
4. a) What is oxidation?
b) Can we call a chemical reaction an oxidation reaction in which hydrogen is removed?
c) Give an example of everyday life where redox reaction takes place.
5. a) What is corrosion?
b) Give an example.
c) What are the requirements for corrosion?
ORAL QUESTIONS
1. What is opposite to combination reaction?
2. To pack food articles, why do manufacturers flush out oxygen with nitrogen?
3. What is spoiling of food called, when kept for a long time?
4. What is the chemical reaction called, in which heat is evolved?
5. Silver articles get black coating. Name the phenomenon.
6. Which gas is evolved when acid is added to lime stone?
7. When a more reactive metal displaces a less reactive metal in solution, what is the reaction
called?
8. What sign (+ or -) is given to exothermic reaction?
9. Which of the two is a redox reaction?
a) Displacement
b) Double displacement
10. What is one important similarity between rusting and burning?
QUIZ - WHO AM I
1. I am symbolic representation of a chemical change.
2. I am a metal which go on losing weight when constantly exposed to air and moisture.
3. I conduct electric current and get a green coating when exposed to humid atmosphere for long.
4. My blue colour starts fading when zinc metal is added to my aqueous solution.
5. I get reduced in a redox reaction.
6. I am formed during a chemical change.
7. I separate reactants from products when a chemical reaction is represented by a chemical
equation.

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8. I give a name to the reaction between acids and bases.
9. I am a chemical reaction which represents digestion of food in our body/
10. I am a process which is used to prevent rusting of iron objects / articles.
Value based questions:
1. . Anjali told her chemistry teacher that bio- fuels should be used instead of fossil fuels. She read in
science magazine that researchers have found that one of the most common bacteria E. coli can digest
simple sugar from plant waste and turn it into valuable bio-fuel. It can convert a renewable non food
plant jatropha to fuel.we need to put it in our food stock, the bacteria converts feed stock into fuel
which is oil that you just scrap of f the tap. Bio-fuels made from plants and animal fat, are alternative to
petroleum based fuel.
c) (a) what is bio-fuel?
d) (b) what are advantage of bio-fuel?
e) (c)is preparation of bio-fuel a chemical or physical process?
f) (d) why is bio- fuel better than petroleum products?
g) (e)what values toes are possessed by Anjali who wants to use bio-fuel?
2. Ajay, a student of chemistry was performing chemical reaction between sodium thiosulphate and
HCl. He found that time required to appear turbidity increase when concentration of HCl or sodium
thiosulphate for both decreases.
Answer th e following questions based on above information:
(a) Mention the reason for appearance of turbidity.
(b) Write the chemical reaction involved.
(c) Mention the value associated with above experiment.

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CHAPTER- 2
ACIDS, BASES AND SALTS
GIST OF THE LESSON
1) Acids are sour in taste, turn blue litmus red, and dissolve in water to release H+
ions e.g. HCl, H2SO4,
HNO3 etc.
2) Bases are bitter in taste, have soapy touch, turn red litmus blue and give hydroxide ions in solution.
e.g. NaOH, KOH etc.
3) A salt is a compound which is formed by neutralization reaction between an acid and base.
e.g. sodium chloride.
3) Indicators – Indicators are substances which indicate the acidic or basic nature of the solution
by their colour change.
The colour of some acid – base indicators in acidic and basic medium are given below
Sr.
No.
INDICATORS COLOUR IN
ACIDIC
MEDIUM
COLOUR IN
BASIC MEDIUM
1 Litmus solution Red Blue
2 Methyl Orange Pink Orange
3 Phenolphthalein Colourless Pink
4 Methyl red Yellow Red
5) Chemical properties of acids:
i) Acids react with active metals to give hydrogen gas.
Zn + H2SO4ZnSO4 + H2
ii) Acids react with metal carbonate and metal hydrogen carbonate to give carbon dioxide.
NaHCO3 +HCl NaCl + H2O + CO2
iii) Acids react with bases to give salt and water. This reaction is called as neutralization reaction.
NaOH + HCl  NaCl +H2O
iv) Acids react with metals oxides to give salt and water.
CuO + H2SO4  CuSO4 + H2O
6) Chemical properties of Bases:
i) Reaction with Metals - Certain reactive metals such as Zinc, Aluminium, and Tin react with alkali solutions on
heating and hydrogen gas is evolved.
2NaOH + Zn  Na2ZnO2 +H2
ii) Reaction with acids -Bases react with acids to form salt and water.
KOH +HCl  KCl +H2O
iii) Reaction with Non -metallic oxides – These oxides are generally acidic in nature. They react with bases to
form salt and water.
2NaOH + CO2 Na2CO3 + H2O
7) PH Scale: The concentration of hydrogen ion in solution is expressed in terms of pH. The pH of a solution is
defined as the negative logarithm of hydrogen ion concentration in moles per liter.
pH = - log [H+
]
For water or neutral solutions, pH = 7 ; For acidic solutions, pH < 7; For basic solutions, pH > 7
8) Some Important Chemical Compounds:
a)Common Salt (NaCl)

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Sodium chloride is known as common salt. Its main source is sea water. It is also exists in the
form of rocks and is called rock salt.
Common salt is an important component of our food. It is also used for preparing sodium hydroxide, baking
soda, washing soda etc.
b)Sodium Hydroxide or Caustic Soda (NaOH)
It is prepared by passing electricity through an aqueous solution of sodium chloride also known as brine.
2NaCl (aq) + 2 H2O (l)  2NaOH (aq) + Cl2 (g) + H2 (g)
This process is known as chlor-alkali process.
Properties:
1. It is white translucent solid.
2. Crystals of sodium hydroxide are deliquescent.
3. It is readily soluble in water and gives strong alkaline solution.
c) Bleaching Powder (CaOCl2)
Its chemical name is calcium oxychloride. It is prepared by passing chlorine gas through dry slaked lime.
Ca (OH) 2 + Cl2CaOCl2 + H2O
Uses –
1. For bleaching cotton and linen in textile industry and wood pulp in paper industry
2. For disinfecting drinking water.
d) Baking Soda (NaHCO3)
Chemical name is Sodium hydrogen carbonate.
It is prepared by passing CO2 gas through brine solution saturated with ammonia.
NaCl + H2O +CO2 +NH3 NH4Cl + NaHCO3
Properties:
1. It is white crystalline solid and sparingly soluble in water at room temperature.
2. On heating it decomposes to give sodium carbonate and carbon dioxide.
3. It reacts with acids to give carbon dioxide gas.
4. It aqueous solution is weak alkaline due to hydrolysis.
Uses:
1. It is used in soda – acid fire extinguisher.
2. It acts as mild antiseptic and antacid.
3. It is used as a component of baking powder. In addition to sodium hydrogen carbonate baking soda contains
tartaric acid.
e) Washing Soda (Na2CO3.10 H2O)
Chemical name is sodium carbonate decahydrate.
It is prepared by heating baking soda. Recrystallisation of sodium carbonate gives washing soda.
2NaHCO3 Na2CO3 +H2O +CO2
Na2CO3 +10 H2O  Na2CO3. 10 H2O
Uses:
1. It is used for removing permanent hardness of water.
2. It is used in glass, soap and paper industries.
3. It can be used as a cleaning agent for domestic purposes.
f) Plaster of Paris (CaSO4.1/2H2O)
Its chemical name is calcium sulphate hemihydrates. It is obtained by heating Gypsum upto 373K.

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CaSO4.2H2O  CaSO4.1/2H2O + 11/2H2O
On treatment with water it is again converted into gypsum and sets as a hard mass.
CaSO4.1/2H2O+11/2H2OCaSO4.2H2O
Uses:-
1. It is used by doctors for setting fractured bones.
2. It is used for making statues, models and other decorative materials.

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MIND MAP
ACID, BASES AND
SALTS
ACIDS BASES
PHYSICAL
PROPERTIES
Corrosive
Blue litmus turns
red,
Sour to taste,
Give H
+
ions
PHYSICAL
PROPERTIES
Soapy to touch,
Red litmus turns
blue,
Bitter to taste
Gives OH¯ ions
INDICATORS
Indicates whether
a substance is
acidic, basic or
neutral
pH Scale
SALTS
Formed when an acid and
a base reacts with each
other
Common salt
NaCl
Bleaching powder
CaOCl2
Baking soda
NaHCO3
Washing soda
Na2CO3.10H2O
Plaster of paris
CaSO4.½H2O

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ACID, BASES AND SALTS
PRACTICE QUESTIONS FOR FORMATIVE ASSESSMENT I
Q.PAPER
Instructions:
1) Name the gas formed when sodium hydroxide reacts with zinc.
2) Write the chemical name of baking soda.
3) What happens when gypsum is heated at 373K?
4) Which has a higher pH value 1M HCl or 1M NaOH solution?
5) Name the acid present in vinegar.
6) What is meant by ‘Water of Crystallisation’ of a substance? Describe an activity to show that.
7) Why does tooth decay start when the pH of mouth is lower than 5.5?
8) What is baking powder? How does it make the cake soft and spongy?
9) Give Arrhenius definition of an acid and a base. Choose strong acid and strong base from the following:
CH3COOH, NH4OH, KOH, HCl
10) What happens when nitric acid is added to egg shell? Give the chemical equation.
11) A student prepared solutions of an acid and a base in two separate beakers. She forgot to label the
solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless, how
will she distinguish between the two?
12) Identify the compound ‘X’ on the basis of the reactions given below. Write the names and chemical
formulae of A, B, C
+ Zn
(A) + H2 (g)
Compound X
+HCl
(B) + H2O
+ CH3COOH
(C) + H2O
13) How is plaster of Paris prepared? What is its chemical formula? Write is chemical name.
14)
a) Define strong acid and weak acid.
b) Name the acids present in tomato and tamarind.
c) A student working in the laboratory added some water to a syrupy liquid taken in tube. The tube
immediately cracked and the liquid escaped out, that produced blisters on the skin of the student. Why?
HOTS QUESTIONS
Q.1. In one of the industrial process used for manufacture of sodium hydroxide, a gas ‘X’ is formed as by –
product. The gas ‘X’ reacts with lime water to give a compound ‘Y’ which is used as a bleaching agent
in chemical industry. Identify ‘X’ and ‘Y’ giving the chemical equation of the reaction.
Ans. In the manufacture of sodium hydroxide, hydrogen gas and chlorine gas (X) are formed as by

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products. When chlorine gas (X) reacts with lime water, it forms calcium oxy chloride (bleaching
powder) Y.
2NaCl (aq) + 2 H2O (L) 2NaOH (Aq) + Cl2 (G) + H2 (G)
‘X’  Cl2 gas
Ca(OH)2 + Cl2 CaOCl2 + H2O
Q.2. Dry hydrogen chloride gas does not turn blue litmus, whereas hydrochloric acid does. Why?
Ans. In the dry state, hydrogen chloride (HCl) does not release H+
ions. Therefore, it cannot behave as an
acid. When dissolved in water, it forms hydrochloric acid. It dissociates to give H+
ions in solution and
behaves as an acid.
Q.3. A metal carbonate X on reacting with an acid gives a gas which when passed through a solution Y
gives the carbonate back. On the other hand a gas G that is obtained at anode during electrolysis of
brine is passed on dry Y, it gives a compound Z, used for disinfecting drinking water. identify X, Y, G
and Z
Q. 4 Name the properties responsible for the following uses of baking powder. (i) Baking industry (ii) As
an antacid (ii) As soda-acid fire extinguisher.
Q. 5 A dry pellet of common base B, when kept in open absorbs moisture and turns sticky. The compound
is also a by product of chlor alkali process. Identify B. what type of reaction occur when B is treated
with an acidic oxide? Write a balanced chemical equation for one such solution.
Q. 6 What effect does an increase in concentration of ‘H’ ions in a solution have on the pH of a solution
Q. 7 Fresh milk has a pH Of 6. When it changes to curd, will its pH value increase or decrease? Why?
Q. 8 How does the flow of acid rain water into a river make the survival of aquatic life in a river difficult?
Q. 9 Arrange in the increasing order of their pH values: NaOH solution, Blood, Lemon juice,
Q. 10 Two solutions A and B have pH values of 5 and 8 respectively. Which solution will be basic in nature?
Q. 11 Why does an aqueous solution of acid conduct electricity?
Q. 12 How is alkali different from a base?
FA II
ACIDS, BASES AND SALTS
ORAL QUESTIONS – (Conversation Type)
1. a) Acids are sour in taste. Is it a way to find whether a substance is an acid or a base?
b) What is other physical test?
c) Any test with solid acid?
d) Can you check the evolution of CO2 chemically?
2. a) What are acids?
b) Can presence of H+
ion in water be estimated? How?
c) How is pH related to strength of an acid?
d) Name one strong acid and one weak acid.
3. a) What are salts?
b) How many types of salts are formed?
c) What are neutral salts?
d) What do you mean by acidic salts?
e) Define basic salts.

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f) Give the corresponding acid and base from which sodium carbonate is formed.
4. a) What is common salt?
b) Why does common salt become moist in rainy season?
c) How is it used as a freezing mixture?
d) Name two important laboratory chemicals prepared from common salt on large scale.
5. a) What is washing soda?
b) Name the process by which sodium carbonate is manufacture.
c) What are the raw materials used in the preparation of washing soda?
d) Sodium carbonate is obtained from another carbonate on heating. Name it.
6. a) Name the substance used for bleaching cotton and wood pulp in textiles.
b) What is its chemical name?
c) How is it manufactured?
d) What is slaked lime?
e) Why does bleaching powder smell of chlorine?
ORAL QUESTIONS
1. Name the acid present in lemon juice.
2. What is the chemical difference between washing soda and baking powder?
3. Name the acid present in ant sting.
4. What is the ideal pH of the soil for the healthy growth of a plant?
5. At what pH the mouth teeth start decaying?
6. How is pH of an acid solution affected when it is diluted?
7. Name the gas responsible for extinguishing fire in a soda – acid fire extinguisher.
8. Out of glucose and acetic acid which one will conduct electricity in water?
9. What is the pH of blood?
10. What is the chemical name of the compound which has the property of hardening when mixed
with water?
QUIZ – WHO AM I
1. I can roughly measure pH value from 0 – 14.
2. I am called antichlor and am used to remove excess chlorine from clothes when treated with
bleaching powder.
3. I am a product of gypsum and am used to making chalks and fire proof materials.
4. I am a compound of calcium and can be used for disinfecting drinking water as well as for
decolourisation.
5. I give different smell in acid and base solution.
6. I am an oxide capable of showing properties for both acids and bases.
7. I am a covalent compound and conducts electricity in aqueous medium.
8. I am a salt of potassium hydroxide and nitric acid.
9. I am the term used when a solid becomes liquid when exposed to moist air.
10. I am derived from tomato and turn blue litmus into red.
1. A student accidently spills concentrated H2SO4 on his hand. Before the teacher get to know
his friend washed his hand with water and also with soap but the burning sensation on hand
still continued. His friend then rubs solid sodium bicarbonate on his hand and then washed
with water, finally the burning sensation is relieved.
Answer the following questions based on above situation.
(I) Mention the values shown by students.
(II) Can you recommend any other substance available in the laboratory which can be used

25
instead of sodium bicarbonate?
(III) Write the chemical reaction involved in the treatment of acid burn with sodium
bicarbonate.
2. Anchal loves to eat chips, burgers and chocolates. Her parents always discourage to eat junk
food.
Answer the following questions based on above situation:
(a)why do you think Anchal’s parents do not let her do not eat junk food.
(b) what values are they promoting?
(c)how can children be persuaded to eat healthy food?

26
CHAPTER – 3
METALS AND NON – METALS
GIST OF THE LESSON
Elements are classified broadly into two categories on the basis of properties:
Metals: Iron, Zinc, Copper, Aluminium etc.
Non – metals: Chlorine, Nitrogen, Hydrogen, Oxygen, Sulphur etc.
Apart from metals and non-metals some elements show properties of both metals and non – metals,
e.g. Silicon, Arsenic, Germanium .They are called metalloids
Comparison of physical and chemical properties of metals and non – metals:-
Sr.
No.
Property Metals Non-Metals
1 Physical
State
Metals are solid at room
temperature. Except
mercury and gallium.
Non-metals generally
exist as solids and gases,
except Bromine.
2 Melting and
boiling points
Metals generally have
high m.pt and b.pt except
gallium and cesium.
Non-metals have low
m.pt and b.pt except
diamond and graphite.
3 Density Generally high. Generally low.
4 Malleability
and Ductility
Malleable and ductile. Neither malleable nor
ductile.
5 Electrical and
thermal
conductivity
Good conductors of heat
and electricity.
Generally poor
conductors of heat and
electricity except
graphite.
6 Lustre Possessing shining or
lustre.
Do not have lustre
except iodine.
7 Sonorous
sound
Give sonorous sound
when struck.
Does not give sonorous
sound.
8 Hardness Generally hard except Na,
K
Solid non-metals are
generally soft except
diamond.
Comparison of Chemical Properties of Metals and Non-metals:-
1 Reaction
with Oxygen
Metal + Oxygen Metal
oxide
4Na(s) + O2(g)  2Na2O(s)
4Al(s) + 3O2(g)  2Al2O3
Metals form basic oxides
Zn and Al form amphoteric
oxides (they show the
properties of both acidic and
Non-metal + Oxygen 
Non-metal oxide
C + O2 CO2
S + O2 SO2
Non-metals form acidic
oxides
CO and H2O are neutral
oxides(they are neither

27
basic oxides)
Most of the metal oxides are
insoluble in water
Some of them dissolve to
form Alkali
Na2O(s) + H2O(l) 
2NaOH(aq)
acidic nor basic in nature)
Non-metal oxides are
soluble in water
They dissolve in water to
form acids
SO2 + H2O  H2SO3
2 Reaction
with water
Metals react with water to
form metal oxides or metal
hydroxide and H2 gas is
released.
2Na(s) + 2H2O(l)  2NaOH +
H2(g) +
heat
Non-metals do not react
with water, steam to
evolve hydrogen gas.
Because Non-metals
cannot give electrons to
hydrogen in water so that it
can be released as H2 gas.
3 Reaction
with dilute
Acids
Metal + Acid  Metal salt
+Hydrogen
HCl
Mg(s) + 2HCl(aq)  MgCl2(aq)
+ H2(g)
H2SO4
2Na(s) + H2SO4 Na2SO4(aq)
+H2(g)
HNO3
Metal + HNO3 H2 gas is not
displaced.
Reason- HNO3 is strong
oxidizing agent.
Non-metals do not react
with acids to release H2 gas
Reason- Non-metals
cannot loose electrons and
give it to Hydrogen ions of
acids so that the gas is
released.
Mn + 2HNO3 Mn(NO3)2 +
H2
H2 gas from HNO3
4 Reaction
with salt
solutions
When metals react with salt
solution, more reactive metal
will displace a less reactive
metal from its salt solution.
CuSO4(aq) + Zn(s) 
ZnSO4(aq) + Cu(s)
When non-metals react
with salt solution, more
reactive non-metal will
displace a less reactive
non-metal from its salt
solution.
2NaBr(aq) + Cl2(g) 
2NaCl(aq) + Br2(aq)
5 Reaction
with Chlorine
Metal + Chlorine  Metal
Chloride
ionic bond is formed.
Therefore Ionic compound is
obtained. 2Na +
Cl2 2NaCl
Non-metal + Chlorine
Non-metal Chloride
covalent bond is formed.
Therefore covalent
compound is obtained.
H2(g) + Cl2 2HCl
6 Reaction
with
Hydrogen
Metals react with hydrogen
to form metal hydride
This reaction takes place only
for most reactive metals.
2Na(s) + H2(g)  2NaH(s)
Non-metals react with
hydrogen to form hydrides
H2(g) + S(l)  H2S(g)

28
Properties of ionic compounds
1. Physical nature:solid and hard due to strong force of attraction. (generally brittle)
2. Melting point and boiling point:have high M.P and B.P, as large amount of heat energy is
required to break strong ionic attraction.
3. Solubility: soluble in water and insoluble in kerosene and petrol.
4. Conduction of electricity:ionic compounds in solid state-----does not conduct electricity.
Reason—Ions can not move due to rigid solid structure. Ionic compounds conduct electricity in
molten state or aqueous solutions.
Reason-- Ions can move freely since the electrostatic forces of attraction between the oppositely
charged ions are overcome due to heat.
Occurrence of metals.
It occurs in Earths crust, sea-water
Elements or compounds, occuring naturally Minerals that contain very high percentage
in the earth’s crust of a perticular metal and these metals can be
extracted economically on a large scale.
e.g. Bauxite ore → Aluminium
Haematite → Iron
Minerals Ores

30
MIND MAP
METALS AND NON -
METALS
METALS
PHYSICAL PROPERTIES
 Solid
 High M .P & B. P
 High density
 Malleable & ductile
 Good conductor of
heat and electricity
CHEMICAL PROPERTIES
 Metal + O2  metal oxide
 Metal + H2O metal
hydroxide/ Oxide
 Metal + dil. Acid salt + H2
 Metal + Cl2 metal chloride
 Metal + H2metal hydride
NON-METAL
PHYSICAL PROPERTIES
 Solid, liquid and gas
 Not malleable & ductile
 Low M.P & B.P
 Poor conductor of heat
electricity
CHEMICAL PROPERTIES
 Non-metal + O2 Non-metal
oxide
 Non-metal + steamH2
 Non-metal + acidno reaction
 Non-metal + chlorinenon-
metal chloride
 Non-metal + hydrogennon-
metal hydride

32
PRACTICE QUESTIONS FORMATIVE ASSESSMENT I
Q.PAPER
Instructions:
1) Which metal other than mercury is liquid at room temperature?
2) Why the item made of silver turns black when exposed to air?
3) Which non – metal is lustrous?
4) What is an amalgam?
5) What is the nature of oxides of metal?
6) Give reasons for the following:
a) Na, K and Ca metals form hydrides by combination with hydrogen gas, but most other metals do not.
b) Metals conduct electricity.
7) Write the equations for the reactions of:
a) Iron with steam.
b) Calcium and potassium with water.
8) What is activity series? How does it help us in predicting the relative reactivities of various metals?
9) (a) What is the difference between sodium atom and sodium ion?
(b)why are ionic compounds usually hard?
10)
a) Write electron dot structure for sodium and oxygen.
b) Show the formation of Na2O by electron transfer.
c) What are the ions present in these compounds?
11) Write three properties of ionic compounds.
12) Explain how a metal low in the activity series can be extracted. Write suitable example.
13) Give reasons:
a) Platinum, gold and silver are used to make jewellery.
b) Sodium, potassium and lithium are stored under oil.
c) Aluminium is a highly reactive metal; still it is used to make utensils for cooking.
14) Name the following:
a) A non – metal that is a good conductor of electricity.
b) A metallic oxide which cannot be reduced by coke.
c) A metallic oxide which is amphoteric in nature.
d) A non – metallic oxide which is neutral.
e) Principal ore of aluminium.

33
HOTS QUESTIONS (SOLVED / UNSOLVED)
Q.1 a) What are amphoteric oxides? Choose the amphoteric oxides from amongst the following:
Na2O, ZnO, Al2O3, CO2, H2O
b) Why is it that non metals do not displace hydrogen from dilute acid?
Ans. a) The oxides which are acidic as well as basic in nature are called amphoteric oxides. ZnO
and Al2O3are amphoteric oxides.
b) Non metals can not loose electrons so that H+
ions become hydrogen gas.
Q.2. What is anodizing? What is its use?
Ans. The process of forming thick oxide layer of aluminium oxide that makes it resistant to further
corrosion.
Q.3. What is Aqua regia? What is its use?
Ans. It is a mixture of concentrated HCl and concentrated HNO3 in the ratio 3:1. It can dissolve gold and
platinum.
Q.4. Give reason: Aluminium is highly reactive metal, but it is used to make utensils for cooking.
Q.5. Explain why (a) Iron articles are frequently painted. (b) Iron sheets are coated with Zinc layer.
Q.6 On adding dilute HCl acid to copper oxide powder, the solution formed is blue – green. Predict the
new compound formed which imparts a blue – green colour to the solution? Write its equation.
Q.7. Name the property of metal used in the following cases- (i) Aluminium foil (ii) Metal jewellery (iii)
Cable wires (iv) Bells
Q.8. How can you prove that Zinc is more reactive than Copper?
Q.9. Draw and explain the electrolytic refining of impure Copper.
Q.10. Why is Aluminium extracted from Alumina by electrolytic reduction and not by reducing it with
Carbon?
Q.11 Write 3 points of difference between Calcination & Roasting?
Q.12 Write 5 points of difference between Ionic compound and covalent compound.
Q.13 What is thermit reaction? Give its one use.
Q.14 ‘M’ is an element which is out of Cu, Fe, Al, Na. it shows following properties:
(a) One of its ore is rich in M2O3.
(b) M2O3 is not affected by water.
(c) It corrodes easily.
(d) It forms two chloride MCl2 a.nd MCl3. Identify’M’
Q. 15 Magnesium when reacts with hot water, starts floating. Why?
Q. 16. Carbon can reduce copper oxide to copper but not CaO to Ca. Why?
FA II
ORAL QUESTIONS
1. Name the metal which is a liquid.
2. Name the non – metal which shows lustre.
3. Name the lightest metal.
4. Name the metal with highest density.
5. Name the property of the metals by virtue of which these can be beaten into sheets
6. Name the property of the metals by virtue of which these can be drawn into wires.
7. Name the element which is kept in water.

34
8. Name the metal used for galvanisation of iron.
9. Mercury is liquid and a good conductor of heat. How is this property utilized?
QUIZ – WHO AM I
1. I am a property of metals which appears at lower temperatures.
2. I am noble conductor of heat and electricity.
3. Though I get corroded in atmosphere but still find wide applications for making kitchen
utensils.
4. I am a metal but very soft and cannot be kept in the open.
5. I am called a series and play a significant role when a metal reacts with solutions of other
metal salts.
6. Scientists / Industrialists use me to extract metals profitably and economically.
7. I am a process to refine metals of high reactivity.
8. I am a process associated with wasting away of metals by the action of atmospheric gases and
moisture
9. I am homogenous and not a compound though my formation least to altering the properties
of metals involved.
10. We belong to the same category of elements but still combine to form molecules /
compounds.
1. shivam helps his friend Rohan in studies. Shivam is topper in the class. Rohan also improved his performance.
They like each other and they are good friends.
(a)what values are proposed by Shivam?
(b)what type of bond exist between Rohan and Shivam?
(c )why are ionic bonds strong?
3. Mrs. Sharma has gone to the jewellers to buy jewellery. She asked the jeweller if the jewellery is made up of
pure gold. The jeweller assured her that it is 100% gold and nothing has been mixed in it . Mrs Sharma is
happy and buys the necklace.
Answer the following question based on the above information:
(a) Was the jeweller right in saying that the necklace is made up of 100% gold?
(b) What values are promoted by jeweller?
(c) What precaution you take while purchasing the gold jewellery?
(d) Why does govt. insist on purchasing hallmarked jewellery?

35
CHAPTER 6 -LIFE PROCESSES
KEY CONCEPTS & GIST OF THE LESSON
 Life processes – The processes that are necessary for an organism to stay alive. Eg. Nutrition, respiration,
etc.
 Criteria of life- (i) Growth (ii) Movement
 Nutrition- The process in which an organism takes in food, utilizes it to get energy, for growth, repair
and maintenance, etc. and excretes the waste materials from the body.
 Types of nutrition
1. Autotrophic nutrition(Auto =self: trophos = nourishment) E.g. Plants, Algae, blue green
algae(Cyanobacteria).
o Process – Photosynthesis(Photo=light; Synthesis= to combine)
o Raw materials- (i) Carbon dioxide (ii)Water
o Equation- sunlight
o 6CO2 + 12 H2O C6H12O6 + 6O2 + 6H2O
Chlorophyll (Glucose)
o Energy conversion- Light/Solar energy to Chemical energy
o Role off Chlorophyll- To trap the sun’s energy for photosynthesis
o Factors- (i) Carbon dioxide (ii) Water(iii) Light (iv) Temperature
o Events/ Steps of photosynthesis-
(i) Absorption of light energy by chlorophyll
(ii) Conversion of light energy to chemical energy & Splitting of water molecule into
Hydrogen & oxygen
(iii) Reduction of Carbon dioxide to Carbohydrate
o Gaseous exchange- (i) Gas used- Carbon dioxide
(ii) By product - Oxygen
o Source of raw materials-
(i) Carbon dioxide –Land plants- Air, Aquatic plants- Water
(ii) Water & Minerals - Soil
2. Heterotrophic nutrition (Hetero =others: trophos = nourishment) Eg. Animals, plants lacking
chlorophyll like fungi.
(a) Saprophytic nutrition: Organisms feeds on dead decaying plants or animals material. E.g. Fungi, Bacteria
(b) Parasitic nutrition: Organisms obtain food from the body of another living (host)
o Endoparasite: Parasite lives inside the body of the host e.g. tapeworm, roundworm.
o Exoparasite: Parasite lives on the body of the host. E.g. lice, leech.
Note- The parasite benefits while the host is usually harmed e.g. Cuscuta-plant parasite (amarbel),
plasmodium (malarial parasite).
(c) Holozoic nutrition: Organism (mostly animals) take in whole food and then digest it into smaller particles
with enzyme. Eg.Amoeba, Paramoecium.Animals, human beings.
o Steps in Holozoic nutrition
(i) Ingestion: taking in of food.
(ii) Digestion: breaking down of complex food into simpler, absorbable form.
(iii) Absorption : absorption of digested food nutrients like amino acids, glucose, fatty acid
and glycerol.
(iv) Assimilation: Utilization of digested food from the body.
(v) Egestion: Removing undigested food from the body

36
o Nutrition in human beings
 Alimentary canal-
Mouth → Oesophagus → Stomach → Small intestine → Large intestine
 Important gland/juices
(Refer to figure 6.6 page no.97 of N.C.E.R.T Text book)
Organ Gland Enzyme/Juice Function
Mouth Salivary glands Salivary Amylase Converts starch into sugar
Stomach Gastric glands Gastric juice-
(i) Hydrochloric
acid →
(ii) Pepsin →
(iii) Mucus →
(a) Kills harmful bacteria that
enters with the food.
(b) Makes the medium acidic for
activation of pepsin
(c) Regulate the cardiac sphincter of
stomach
Digests proteins
Protects the inner lining of the stomach
from the corrosive action of
Hydrochloric acid.
Small intestine 1) Liver
2) Pancreas
(i) Bile juice →
(ii) Pancreatic
Juice
 Amylase →
 Trypsin →
 Lipase →
(a) Makes the medium alkaline
for the activation of trypsin.
(b) Breaks down large fat
molecules into smaller globules
so that enzymes can act upon
them(emulsification)
Converts Carbohydrates to glucose
Converts Proteins to Amino acids
Converts Fats into Fatty acids &
Glycerol
 Peristaltic movements- Rhythmic contraction of muscles of the lining of Alimentary canal to push
the food forward.
 Sphincter muscle- Helps in the exit of food from the stomach.
 Villi- Small finger like projections on the walls of-
(vi) Small intestine- To increase the surface area for the absorption of food.
(vii) Large intestine- For absorption of water.
 Respiration- The process by which digested food is broken down with the help of Oxygen to release
energy(oxidation of food)
o Types of respiration- (i) Aerobic respiration (ii)Anaerobic respiration

37
Aerobic respiration Anaerobic respiration
1. Takes place in presence of Oxygen.
2. End products- Carbon dioxide & Water
3. More energy is released.
4. Takes place in Cytoplasm & Mitochondria
5. Complete oxidation of glucose takes place.
6. It occurs in most organisms.
7. Equation-
Glucose→ Pyruvate→ CO2 + H2O + Energy
(38 ATP)
1. Takes place in absence of Oxygen.
2. End products- Ethanol & Carbon dioxide or Lactic
acid.
3. Less energy is released.
4. Takes place in only in Cytoplasm.
5. Incomplete oxidation of glucose takes place.
6. It occurs in certain bacteria, yeast & certain
tissues of higher organisms. E.g. In humans during
vigorous exercise, when the demand for Oxygen is
more than the supply, muscle cells respire
anaerobically for some time.
7. Equation-
In Yeast-(Alcoholic fermentation)
Glucose→ Pyruvate→ Ethanol + CO2 + Energy
In muscle cells – (lactic acid fermentation)
Glucose→ Pyruvate (3 Carbon molecule) → Lactic
acid + Energy
o Some common features of Respiratory organs- (i) Large
surface area- for greater rate of diffusion of respiratory gases. (ii) Thin permeable
walls – to ensure easy diffusion & exchange of gases. (iii) Extensive blood supply-
Respiratory organs are richly supplied with blood vessels for quick transport of gases.
o Gaseous exchange in plants-
 Process – Diffusion
 Direction of diffusion depends on- (i) Environmental conditions
(ii) Requirement of the plant.
 Day time- Carbon dioxide given out during respiration is used for photosynthesis. Therefore only
Oxygen is released, which is a major activity during the day.
 Night time – Only respiration takes place. Therefore only Carbon dioxide is released, which is a
major activity during the night.
o Gaseous exchange in animals-
 Terrestrial animals- take Oxygen from the atmosphere.
 Aquatic animals- take Oxygen dissolved in water. (Oxygen content is low in water, therefore
they breathe faster.
o Human Respiratory system- External nostrils →
Nasal cavity → Trachea→ Bronchi → Bronchioles →Alveoli
 Rings of cartilage present in the throat ensure that the trachea (air passage) does not collapse
when there is less air in it.
 Lungs – (i) Present in the thoracic cavity.

38
(ii) They are spongy, elastic bags consisting of Bronchi,
Bronchioles and Alveoli
Refer to figure 6.9 page no. 104 of N.C.E.R.T Text book)
o Respiration occurs in two phases-
o (i) External-Breathing, which is a mechanical process. (ii) Internal -
Cellular respiration
o Mechanism of breathing – It includes : (i)Inhalation (ii) Exhalation
o Exchange of gases-
 Unicellular organisms- By Diffusion
 Animals- (i) As the body size is large, diffusion alone is not enough.
(ii) Respiratory pigments also required.
(iii) Respiratory pigment in human beings is Haemoglobin,
which is present in red blood corpuscles.
(iv) It has very high affinity for Oxygen.
(iv) Carbon dioxide is more soluble in water thanOxygen, so it
Gets dissolves in blood and is thus transported.
 Transportation
o Transportation in human beings-
 Blood- (i) It is a fluid connective tissue.
(ii) Components- (1) Fluid medium- Plasma
(2) Red blood corpuscles
(3) White blood corpuscles
(4) Platelets suspended in plasma
(iii) Plasma transports food, Oxygen, Carbon dioxide,
Nitrogenous wastes, etc.
 Functions of blood- (i) Transport of respiratory gases.
(ii) Transport of nutrients.
(iii) Transport of waste products.
(iv) Defence against infection
 Blood vessels- (i) Arteries (ii) Veins (iii) Capillaries
Arteries Veins
1. Thick walled.
2. Deep seated.
3. Carry blood away from the heart.
4. Carry Oxygenated blood.
5. Valves absent.
1. Thin walled.
2. Superficial.
3. Carry blood to the heart.
4. Carry Deoxygenated blood.
5. Valves present

39
Circulatory
system
Heart
2 Upper Chambers(atria)
2 Lower Chambers(ventricles)
Blood
Fluid part(Plasma)
Plasma transports food, Oxygen, Carbon dioxide,
Nitrogenous wastes, etc.
RBC
Contain haemoglobin &
Transport Oxygen
Cellular part WBC Fight against diseases
Platelets Blood clotting
Blood
Vessels
Arteries
Carry blood from heart to
body parts
Veins
Collect blood from body
parts and carry to heart
Capillaries
 Heart- (Refer to figure 6.10 page no. 106 of N.C.E.R.T Text book)
(i) It is a muscular organ, which works as a pump in the circulatory system.
(ii) It is the size of our fist.
(iii) It has two sides, which are separated by a partition so that the oxygenated and
deoxygenated blood do not get mixed up.
(iv) It has four chambers-
Two upper chambers called Atria.
Two lower chambers called Ventricles.
 Working of heart-
Left side- (i) Left atrium relaxes & the Oxygenated blood enters it from
the lungs through the pulmonary vein.
(ii) Left atrium contracts & the blood enters the left ventricle
through the valve.(Bicuspid or mitral valve)
(iii) Left Ventricle contracts and the blood is pumped into the
largest artery ‘Aorta’ and is carried to all parts of the body.
Right side- (i) Right atrium relaxes & the deoxygenated blood from the body enters it
through superior and inferior Vena cava.
(ii) Right atrium contracts & the blood enters the right Ventricle through
the valve(Tricuspid Valve)
(iii) Right Ventricle contracts and the blood is pumped into the Pulmonary
artery and is carried to lungs.
 Valves- Unidirectional to prevent the backward flow of blood.

40
 Pulmonary vein is the only vein that carries Oxygenated blood(from lungs to left side of the
heart)
 Pulmonary artery is the only artery that carries Deoxygenated blood(from right side of the heart
to lungs)
 Double circulation in man- because the blood passes through the heart twice in one complete
cycle of the circulation.
 Capillaries- (i) Form the connection between arteries & veins.
(ii) Walls are one cell thick only for easy exchange of
blood.
 Platelets- Plug the leaks of arteries and veins by clotting the blood.
 Lymph- Extracellular fluid similar to plasma but colourless with lesser protein.
 Function of lymph- (i) Transportation of digested & absorbed fats from
the small intestine.
(ii) Drains excess fluid from the intercellular spaces
back in the blood.
 Higher animals- E.g., birds, mammals.
(i) Oxygenated blood & Deoxygenated blood are completely separate for efficient
Oxygen supply.
(ii) This is to fulfil higher energy needs and to maintain body temperature (warm
blooded animals).
 Amphibians & reptiles- have 3 chambered heart where little mixing of Oxygenated blood &
Deoxygenated blood takes place. Therefore their body temperature varies with the temperature
of the environment. (cold blooded animals)
o Transportation in plants-
 Plants need less energy needs- because they do not move and therefore have a slow transport
system
 Transport of water-
(i) Takes place by xylem tissue present in roots, stem, leaves and is therefore
interconnected.
(ii) Root cells take up ions from the soil, which creates a concentration difference
between root and soil. Column of water therefore rises upwards.
 In very tall plants- transpiration creates a suction pressure, which pulls the water upwards.
 Importance of transpiration-
(i) Helps in upward movement of water in plants.
(ii) It regulates the temperature in plants.
 Transport of food-
(i) Takes place by phloem tissue.
(ii) Movement of prepared food in plants is called translocation.
 Excretion- The biological process of removal of harmful metabolic wastes in living organisms.
 Excretion in human beings-
(Refer to figure 6.13 page no. 110 of N.C.E.R.T Text book)
 Organs of excretory system- (i) Kidneys (iii) Urinary bladder
(ii) Ureters (iv) Urethra
 Kidneys-
(i) Two in number
(ii) Bean shaped

41
(iii) Present in abdomen on either side of the backbone
(iv) Basic unit is nephron.
a. Glomerulus- Group of capillaries (cluster) present in Bowman’s
capsule to receive blood from renal artery and filters it.
b. Bowman’s capsule- Cup shaped structure, which contains glomerulus.
c. Convoluted tubule-is long and reabsorbs vital nutrients like glucose, amino acids,
salts, urea and water.
Note-Vital functions of kidneys- (a) Filtration & removal of Nitrogenous wastes (Urea ,Uric acid)
(b) Reabsorption of vital nutrients
 Ureters- Transport the urine formed in the kidneys to the urinary bladder.
 Urinary bladder- Muscular bag like structure to store urine.
 Urethra- Helps in removal of urine when the Urinary bladder is full.
 Artificial kidney- Principle: Dialysis
 Excretion in plants-
 Gaseous wastes- CO2 in respiration & O2 in photosynthesis are removed by the process of
diffusion.
 Excess water- is removed by transpiration.
 Other wastes- (i) Stored in cellular vacuoles or in leaves, which fall off or as
gums, resins, etc. in old xylem.
(ii) Excreted in soil.
 Important diagrams-
1. Open & close stomata
2. Steps of nutrition in Amoeba
3. Alimentary canal of human beings/ Digestive system of human beings
4. Respiratory system of human beings
5. Structure of heart.
6. Excretory system of human beings
7. Structure of nephron
 Important activities-
1. To prove that chlorophyll is necessary for photosynthesis.
2. To prove that Carbon dioxide is necessary for photosynthesis.
3. To prove that light is necessary for photosynthesis.
4. To prove that product of fermentation is Carbon dioxide.
5. To prove that leaves lose water by transpiration.
6. To study the action of salivary amylase on starch.
7. To demonstrate that Carbon dioxide is present in exhaled air.
8. To demonstrate the process of transpiration in plants.

42
LIFE PROCESS
FORMATIVE ASSESSMENT I
Q.PAPER
Instructions:
1. Name the site of photosynthesis.
2. What is osmoregulation?
3. Name the excretory unit of kidney.
4. What is neuron?
5. Name the term for transport of food from leave to other parts of the plant.
6. Draw the diagram of cross – section of a leaf and label the following in it:
a. Chloroplast
b. Guard cell
c. Lower epidermis
d. Upper epidermis
7. What do you mean by double circulation of blood?
8. Explain why Bile juice does not contain any digestive enzymes, yet it is essential for digestion.
9. How would non – secretion of hydrochloric acid in our stomach affect food digestion? Explain.
10. How does nutrition takes place in Amoeba?
11. Draw a diagram of cross section of human heart. Show the path of flow of blood with the help of arrows.
12. How water is transported upwards in plants?
13. Descried the functioning of nephrons.
14.
a. Draw a diagram of human alimentary canal.
b. Label the following – oesophagus, liver, gall bladder, and duodenum.
c. What is the function of liver in human body?
Q1. Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Ans. The mammals and birds are warm-blooded animals which have high energy needs because they constantly
require energy to maintain their body temperature. It is necessary to separate oxygenated blood and
deoxygenated blood in mammals and birds because such a separation allows a highly efficient supply of oxygen
to the body cells which is required for producing a lot of energy needed by them.
Q2. How is small intestine designed to absorb digested food?
Ans. The inner surface of small intestine has millions of tiny, finger like projections called Villi. The presence of
villi gives the inner walls of the small intestine a very large surface area. The large inner surface area of small
intestine helps in the rapid absorption of the digested food.

43
LIFE PROCESSES
ORAL QUESTIONS
1. Do plants also need oxygen?
2. How does food passes through alimentary canal?
3. What regulate the exit of food from the stomach into small intestine?
4. In which part of the alimentary canal food is completely digested absorbed?
5. In which cell organelle breakdown of pyruvate takes place using oxygen?
6. Which structures stop backward flow of blood in atria and ventricles?
7. The filtered urine is collected in which part of nephron?
8. Which part of the plant excretes some waste substances into the soil?
9. Name the process used to remove urea from the blood.
10. The process by which evaporation of water from the plants mainly through the stomata.
QUIZ
1. Digestion of starch in humans takes from which organ?
2. Absorption of energy takes place in sunlight by the pigment.
3. Is chloroplast is non – lining structure?
4. What is the function of amylase?
5. Name the organ responsible for respiration in fish.
6. Which is more harmful urea or ammonia?
7. Which contains less nitrogenous wastes, the renal vein or renal artery?
8. Draw the diagram of respiratory system or human digestive system.
VALUE BASED QUESTIONS
1. you were standing on the road side, when you saw a family travelling in acar. An ambulance
carrying a patient for dialysis was travelling behind the car. The driver of the car brought his
car to one side of the road and allowed the ambulance to overtake.
(a) what value was shown by the driver?
(b) what is dialysis?
(c)what are the vehicles whom we should give pass while driving?
2. an organ donation camp was organised by govt. in your locality to encourage people for
organ donation but the camp was not very successful. The camp hardly received any response.
(a) what values are possessed by people who wish to donate their organs.
(b) will organ donation agreement affect the donar?
(c) why did the organ donation camp failed?

44
CHAPTER 7 – CONTROL & COORDINATION
 Coordination-The working together of various organs of the body of an organism in a proper manner to
produce appropriate reaction to a stimulus is called coordination.
 Stimulus- The changes in the environment to which an organism responds and reacts is called Stimulus
 Control & coordination in animals- takes place by (i) Nervous system & (ii) Endocrine system
 Nervous system
Stimulus → Receptor organ → Sensory nerve → Brain/Spinal cord
↓
Response ← Effector organ ← Motor nerve
 Endocrine system
Stimulus → Endocrine organ → Secrete hormone → Hormone in blood
↓
Response ← Target organ
 Parts of the Nervous system – (i) Brain (ii) Spinal cord (iii) Nerves (Neurons)
 A Neuron is the structural & functional unit of Nervous system
 Parts of a neuron- (i) Dendrites (ii) Cell body (iii) Axon (iv) Nerve ending
 Synapse- Space/junction between two adjacent nerves is called Synapse.
 Passing of information takes place –(i) By Electric impulse (inside the neuron) and (ii)
In the form of chemicals (At synapse)
 Reflex action- Spontaneous, involuntary and automatic response to a stimulus to protect us from
harmful situations. Eg. On touching a hot object unknowingly we instantly withdraw our hand.
 Reflex arc- The pathway of the reflex action is called Reflex arc.
Stimulus → Receptor organ → Sensory nerve → Spinal cord →→Effector organ→ Response
 Nervous system-
(1) Central Nervous system (CNS)
(i) Brain (ii) Spinal Cord
(2) Peripheral Nervous system (PNS)
(i) Autonomic Nervous system (ii)Voluntary Nervous system
 Brain (i) Centre of coordination of all activities (ii) Thinking is involved (iii) Complex process
 Parts of brain- Refer to figure 7.3 page no. 118 of N.C.E.R.T Text book
Fore brain Mid brain Hind brain

45
(i)
Cerebrum
(ii) Thalamus
(iii) Hypothalamus
---------- (i) Cerebellum
(ii) Pons
(iii) Medulla oblongata
 Fore brain
Cerebrum- (i) Main thinking and largest part of the brain.
(ii) It has 3 main areas-
a. Sensory area- to receive impulses from sense organs viaReceptors
b. Motor area- control voluntary movements.
c. Association areas- Reasoning, learning & intelligence.
Thalamus – It relays sensory information to the Cerebrum
Hypothalamus- It forms the link between Nervous system & Endocrine system
 Mid brain- It connects Fore brain and Hind brain. Controls reflex of eyes & ears
 Hind brain- Connects the Fore brain & Hind brain
Cerebellum – Controls & coordinates muscular movements, maintaining body posture and equilibrium.
Pons- Acts as a bridge between brain & spinal cord
Medulla oblongata- Controls involuntary actions like blood pressure, salivation, vomiting, etc.
 Spinal cord- Cylindrical or tubular structure extending downwards from the Medulla oblongata.
 Protection of the brain & the spinal cord- (i) Bony
outer covering: skull for the brain & vertebral column for the spinal cord.
(ii) Cerebrospinal fluid present in between the three membranes.
 Action caused by Nervous tissue Information →
Nervous tissue → Brain Muscles → Causes action
 Path or action- Nerve
impulse → Muscle cell → Changes shape due to special proteins
↓
Action caused ← Shorter form of muscles ← Change shape & arrangement of cell
 Chemical communication by hormones- (advantages)
(i) Electrical impulses have their limitations because they reach only those cells connected to the
nervous tissue.
(ii) Also the nerve cells cannot generate & transmit impulses continuously.
(iii) Electrical communication is slower.
 Hormones- (i) are chemical messengers secreted by endocrine glands
(ii) Are secreted in small amounts & may act in nearby places or distant places.
(iii) Do not take part in the reaction & are destroyed immediately.
 Hormones are secreted by- Endocrine glands
S.No. Endocrine glands Exocrine glands
1. Ducts absent Ducts present
2. Secrete hormones Secrete enzymes
3. Secreted in blood Secreted in ducts of glands

46
4. Situated away from the site of action Situated near the site of action
 Some glands which act as both endocrine & exocrine
Gland Endocrine function Exocrine function
Pancreas Produces insulin & Glucagon
hormone.
Produces digestive enzyme. (pancreatic
amylase , lipase, trypsin)
Testes Produces hormone Testosterone Produces male gametes (reproductive cells)
Ovaries Produces hormone Oestrogen Produces female gametes (reproductive cells)
 Important Endocrine glands, the hormone they secrete & their function
Endocrine gland Hormone Function
Pituitary gland Growth hormone Body growth, development of bones & muscles
(If excess- Gigantism)
(If less- Dwarfism)
Thyroid gland Thyroxine Regulates carbohydrate, protein & fat metabolism(
If less- Goitre_
Pancreas Produces insulin &
Glucagon hormone
Regulates blood sugar levels (if less diabetes is
caused)
Testes in males Produces hormone
Testosterone
Development of secondary male characters like deep
voice, beard, etc.
Ovaries in
females
Produces hormone
Oestrogen
Development of secondary female characters like
mammary glands, menstrual cycle, maintenance of
pregnancy.
 Coordination in plants- Only chemical coordination is present in plants.
 Tropic movements- The movements of plants in the direction of stimulus (positive) or away from it
(negative) are called tropic movements. E.g. Phototropism, Geotropism. Chemotropism.
Refer to figure 7.4 & 7.5 page no. 121 of N.C.E.R.T Text book)
 Nastic movements -The movements of plants independent of stimuli are called nastic movements. E.g.-
Touch me not plant leaves close when touched(Mimosa pudica)
 Plant hormones (Phytohormones)
Examples- 1.Auxins- Help in growth of root & shoot tips.
2. Gibberellins- Help in vegetative growth
3. Cytokinins- Promote cell division
4. Abscissic acid - Inhibits growth & causes wilting (falling) of leaves
1. Structure of neuron (nerve cell)2.Reflex arc 3.Human brain4.Endocrine glands .
1. To compare taste of sugar and food with open & blocked nostrils.
2. To demonstrate the response of a plant to the direction of light.
3. To demonstrate hydrotropism.

47
MIND MAP
CONTROL AND CO-ORDINATION
ANIMALS
NERVOUS
SYSTEM
ENDOCRINE
SYSTEM
REFLEX ACTION
CNS
PNS
Hormone secreted by
endocrine glands
Reflex arc
Brain, spinal
cord
Neuron
Sensory
Motor
PLANTS
Plant movement
Tropic Nastic
Phytohormones
Growth
promoting
Auxins,
Gibberellins,
Cytokinins,
Ethylene
Growth
inhibiting
AbA
Independent of
stimulusDirection of
stimulus

48
CONTROL AND CO - ORDINATION
Q. PAPER
Instructions:
1. Which endocrine gland is unpaired?
2. Which part of the brain controlled posture and balance of the body?
3. Where in a neuron, conversions of electrical signal to a chemical signal occur?
4. Which gland secretes digestive enzyme as well as hormones?
5. We suddenly withdraw our hand when a pin pricks. Name the type of response involved in this action.
6. What is a tropic movement? Explain with an example.
7. What will happen if intake of iodine in our diet is low?
8. Draw the structure of neuron and label the following on it:
a. Nucleus
b. Dendrite
c. Cell body
d. Axon
9. Why are some patients of diabetes treated by giving injections of insulin?
10. Why is the flow of signals in a synapse from axonal end of one neuron but not the reverse?
11. What are reflex actions? Explain reflex arc.
12. What are the major parts of the brains? Mention the functions of each.
13. How does chemical co – ordination take place in animals?
14.
a. Name the various plant hormones.
b. Give physiological effects of hormones on plant growth and development.
Q1. Which hormone:
1. prepares the body for action?
2. controls the amount of sugar (glucose) in blood?
3. brings about changes in boys at puberty?
4. brings about changes in girls at puberty?
Ans. a) Adrenaline b) Insulin
c) Testosterone d) Oestrogen
Q2. i) Name the hormone produced by thyroid gland.
ii Which mineral is necessary for the synthesis of the above hormone?

49
iii Name the disease suffer from the deficiency of this mineral.
iv Write the function of the above hormones?
Q3. What is chemotropism? Give one example of chemotropism.
ORAL QUESTIONS
1. What is the basic unit of nervous system?
2. How do neuron conduct message from brain to other parts?
3. What do you mean by CNS?
4. What are its main parts?
5. Which part controls reflex action?
6. What are endocrine glands?
7. What is the secretion of endocrine gland called?
8. Name a gland of human body which secretes both enzymes and hormone.
9. Which plant hormone helps in cell division?
10. Which hormones help on stem elongation?
QUIZ
1. Which system of our body is made of organised network for conducting information in the
body?
2. Which part of the neuron receives information?
3. What is the name of the neuron which remains between the sensory neuron and the motor
neuron? Where is it located?
4. Which part of the brain helps us to do activities like riding a cycle and walking in a straight line?
5. What are two major types of muscles we have?
6. What causes change in leave of ‘touch me not’ plant?
7. Which hormone helps us to prepare to combat adverse condition?
8. Name a female sex organ which produces gametes as well as female hormone.
Q1.Mr. Bora has a habit to iron his shirt every morning before going to office. One morning he forgot to keep
the hot iron in proper place and left for office. His two years old daughter touched the iron and her hand got
burnt. Mrs. Bora immediately put the hand of her daughter under a running tap as a first aid.
(a) What value was shown by Mrs. Bora?
(b) How do we react when we touch a hot object?
(c) What other materials commonly cause burn injury?
Q2. Few children in your village have complain of swelling neck. More and more children complained about
swollen necks every month. A villager Hari Slngh in superstitious and he thinks that the village is cursed by a
‘devil’. Shyam is an another villager who thinks it is a disease which needs consultation with the doctor.
(a) do you agree with Hari Singh?
(b) what can be the reason behind the swollen necks of the young children? how can the /
problem be overcome?
(c)what social change is required in the village to make it free from blind faith
(d) what values are shown by Shyam?

50
ELECTRICITY
GIST OF THE LESSON
1. Positive and negative charges: The charge acquired by a glass rod when rubbed with silk is called
positive charge and the charge acquired by an ebonite rod when rubbed with wool is called negative
charge.
2. Coulomb: It is the S.I. unit of charge. One coulomb is defined as that amount of charge which repels an
equal and similar charge with a force of 9 x 109
N when placed in vacuum at a distance of 1 meter from
it. Charge on an electron = -1.6 x 10-19
coulomb.
3. Static and current electricities: Static electricity deals with the electric charges at rest while the current
electricity deals with the electric charges in motion.
4. Conductor: A substance which allows passage of electric charges through it easily is called a ‘conductor’.
A conductor offers very low resistance to the flow of current. For example copper, silver, aluminium etc.
5. Insulator: A substance that has infinitely high resistance and does not allow electric current to flow
through it is called an ‘insulator’. For example rubber, glass, plastic, ebonite etc.
6. Electric current: The flow of electric charges across a cross-section of a conductor constitutes an electric
current. It is defined as the rate of flow of the electric charge through any section of a conductor.
Electric current = Charge/Time
or I = Q/t Electric current is
a scalar quantity.
7. Ampere: It is the S.I. unit of current. If one coulomb of charge flows through any section of a conductor
in one second, then current through it is said to be one ampere.
1 ampere = 1 coulomb/1 second or 1 A = 1C/1s = 1Cs-1
1 milliampere = 1 mA = 10-3
A
1 microampere = 1µA = 10-6
A
8. Electric circuit: The closed path along which electric current flows is called an ‘electric circuit’.
9. Conventional current: Conventionally, the direction of motion of positive charges is taken as the
direction of current. The direction of conventional current is opposite to that of the negatively charged
electrons.
10. Electric field: It is the region around a charged body within which its influence can be experienced.
11. Electrostatic potential: Electrostatic potential at any point in an electric field is defined as the amount of
work done in bringing a unit positive charge from infinity to that point. Its unit is volt. Positive charges
move from higher to lower potential regions. Electrons, being negatively charged, move from lower to
higher potential regions.
12. Potential difference between two points: The Potential difference between two points in an electric
field is the amount of work done in bringing a unit positive charge from one point to another.
Potential difference = Work done/Charge or V = W/Q
Volt is the S. I. Unit of P.D.
13. One volt potential difference: The Potential difference between two points in an electric field is said to
one volt if one joule of work has to be done in bringing a positive charge of one coulomb from one point
to another. 1 volt = 1 joule/1 coulomb or 1 V = 1J/1C
14. Galvanometer: It is device to detect current in an electric circuit.
15. Ammeter: It is device to measure current in a circuit. It is always connected in series in a circuit.
16. Voltmeter: It is a device to measure potential difference. It is always connected in parallel to the
component across which the potential difference is to be measured.
17. Ohm’s law: This law states that the current passing through a conductor is directly proportional to the
potential difference cross its ends, provided the physical conditions like temperature, density etc.

51
remains unchanged.
V α I or V = RI
The proportionality constant R is called resistance of conductor.
18. Resistance: It is a property of a conductor by virtueof which it opposes the flow of current through it. It
is equal to the ratio of the potential difference applied across its ends and the current flowing through
it.
Resistance = Potential difference/Current or R = V/I
19. Ohm: It is the S.I. unit of resistance. A conductor has a resistance of one ohm if a current of one ampere
flows through it on applying a potential difference of one volt across its ends.
1 ohm = 1 volt/1 ampere or 1Ω = 1V/1A
20. Factors on which resistance of a conductor depends: The resistance R of a conductor depends
i) Directly on its length L i.e. R α L.
ii) inversely on its area of cross-section A i.e. R α 1/A
iii) on the nature of material of the conductor.
On combining the above factors, we get
R α L/A
R = ρ* L/A The proportionality constant ρ is called resistivity of conductor.
21. Resistivity: It is defined as the resistance offered by a cube of a material of side 1 m when current flsows
perpendicular to its opposite faces. Its S.I. unit is ohm-meter (Ωm).
Resistivity, ρ = RA/L
22. Equivalent resistance: If a single resistance can replace the combination of resistances in such a manner
that the current in the circuit remains unchanged, then that single resistance is called the equivalent
resistance.
23. Laws of resistances in series:
i) Current through each resistance is same.
ii) Total voltage across the combination = Sum of the voltage drops.
V= V1 + V2 + V3
iii) Voltage drops across any resistor is proportional to its resistance.
V1 = IR1, V2 = IR2, V3 = IR3iv) Equivalent resistance = Sum of the individual resistances.
Rs = R1 + R2 + R3
v) Equivalent resistance is larger than the largest individual resistance.
24. Laws of resistances in parallel:
i) Voltage across each resistance is same and is equal to the applied voltage.
ii) Total current = Sum of the currents through the individual resistances.
I = I1 + I2 + I3
iii) Currents through various resistances are inversely proportional to the individual resistances.
I1 = V/R1, I2 = V/R2, I3 = V/R3iv) Reciprocal of equivalent resistance = Sum of reciprocals of individual
resistances. 1/Rp= 1/R1 + 1/R2 + 1/R3
v) Equivalent resistance is less than the smallest individual resistance.
25. Joule’s law of heating: It states that the heat produced in a conductor is directly proportional to (i) the
square of the current I through it (ii) proportional to its resistances R and
(iii) the time t for which current is passed. Mathematically, it can be expressed as
H = I2
Rt joule = I2
Rt/4.18 cal
OR
H = VIt joule = VIt/4.18cal
Applications-Electric toaster, Electric heater, Fuse wire etc.
26. Electric energy: It is the total work done in maintaining an electric current in an electric circuit for given
time.

52
Electric energy, W = VIt = I2
Rt joule
27. Electrical power: Electrical power is the rate at which electric energy is consumed by an appliance.
P = W/t = VI = I2
R = V2
/R =
28. Watt: It is the S.I. unit of power. The power of an appliance is 1 watt if one ampere of current flows
through it on applying a potential differences of 1 volt across its ends.
1 watt = 1 joule/1 second =1 volt x 1 ampere
or 1 W = 1 Js-1
= 1 VA
1 kilowatt = 1000 W
1KVA=1000 W
29. Kilowatt hour: It is the commercial unit of electrical energy. One kilowatt hour is the electric energy
consumed by an appliance of 1000 watts when used for one hour.
1 kilowatt hour (kWh) = 3.6 x 106
J

53
MIND MAP
ELECTRIC POWER
P=w/t
Unit-Watt (W)
Or P= VI =I2
R = V2
/R=
Unit of Power = Watt = J/sELECTRIC ENERGY
Work = VIT = I 2
RT
Unit of E E – Watt-Hr
or Kwh
1Kwhr= 3.6 x 106
J
P D = work done / charge
V = W /Q
UNIT OF V is Volt
JOULE’S LAW
H = I2
RT
Or H = VIT
Unit of heat energy =Joule(J)
ELECTRICITY
OHM’S LAW
V = IR
Unit of R - Ohm
RESISTANCE(R) = V/I
Unit of R =Ohm(Ώ)
RESISTIVITY = RA / L
Unit of Resistivity –
Ohm.metre (Ώm)
RESISTANCE IN SERIES
RS = R1 + R2 + R3…..
RESISTANCE IN PARALLEL
1/RP = 1/R1 + 1/R2 + 1/R3 …….
I =
Unit of I is Ampere (A)
Ampere = Coulomb/s

54
ELECTRICITY
QUESTION PAPER FOR FORMATIVE ASSESSMENT
Instructions:
1. Define resistivity of material.
2. What is the power of torch bulb rated at 2.5V and 500mA?
3. Why series arrangement not used for connecting domestic electrical appliances in a circuit?
4. How is ammeter connected in the circuit to measure electric current?
5. What is the direction of flow of conventional current?
6. Why is it not advisable to handle electrical appliances with wet hands?
7. Two electric bulbs marked 100W 220V and 200W 200V have tungsten filament of same length.
Which of the two bulbs will have thicker filament?
8. How does the resistance of a wire vary with its area of cross section?
9. Draw the symbols of following components used in circuit diagram.
ii) Battery iii) Switch closed
iv) Resistor of resistance R v) Voltmeter
10. A geyser is rated 1500W, 250V. This geyser is connected to 250V mains. Calculate –
i) The current drawn
ii) The energy consumed in 50hrs.
iii) The cost of energy consumed at Rs. 2.20 per kWh.
11. What is the function of an electric fuse? Name the material used for making fuse. In household
circuit where is fuse connected?
12. What is meant by electric resistance of a conductor? A wire of length “l” and resistance R is
stretched to its twice length. How will its (i) resistance and (ii) resistivity change?
13. a) Draw diagram showing three resistors R1, R2 and R3 in series.
b) Two resistors of resistance 4 and 12
i) In parallel
ii) In series
Calculate the values of equivalent resistance in each case.
HOTS QUESTIONS (SOLVED )
Q.1. Why is the tungsten metal more coiled in the bulb and not installed in straight parallel wire form?
Ans. The coiled wire of tungsten increases the surface area of the wire in very less space so as to emit
more light and helps in glowing with more intensity.
Q.2. Why are fairy decorative lights always connected in parallel?
Ans. When the fairy lights are connected in series the resistance offered will be greater and brightness of
the bulbs will be affected. But in parallel connection all the bulbs will glow with same intensity and if
any one bulb gets fused the other bulbs will continue to glow.
Q.3. What will happen when -
a) Voltmeter is connected in series?

55
b) Ammeter is connected in parallel?
Ans: When voltmeter is connected in series no current flows through the circuit as ideal
voltmeter infinite resistance. When Ammeter is connected in parallel , high current flows
through the ammeter and it gets spoiled.
Q.4 Two metallic wires A and B of same material are connected in parallel. Wire A has
length l and radius r and wire B has length 2l and radius 2r. Compute the ratio of total
resistance of parallel combination and the resistance of wire A.
Ans. Resistance of wire A, R1= ρ l/A = ρl/πr2
.
Resistance of wire B, R2= ρl/2πr2
1/R = 1/R1 +1/R2 = πr2
/ ρl +2 πr2
/ ρl =3 πr2
/ ρl
R = ρl/3 πr2
R/R1 =1/3.
VALUE BASED QUESTION:
(1) Electricity plays an important role in the development of a country. Ram,a student of class X was
studying in the library. After school hours when he came from the library, he found that electric
fans and tubelights of all rooms were ON. He immediately switched OFF all fans and lights and
reported the matter to the Principal.
(i) Comment on the attitude of Ram.
(ii) Why Ram reported the matter to the Principal?
Ans. (i) Ram knows the importance of electricity. He is against the misuse of national resources.
(ii)He reported the matter to prevent the misuse of national resources.

56
CHAPTER-13
MAGNETIC EFFECTS OF ELECTRIC CURRENT
 Magnet: (i) is an object that attracts objects made of iron, cobalt & nickel. (ii)
Comes to rest in North-South direction, when suspended freely.
(iii) Like poles repel each other while unlike poles attract.
 Magnets are used: (i) In radio & stereo speakers, (ii) In refrigerator doors, (iii) on audio & video
cassettes players, (iv) On hard discs & floppies of computers & (v) in children’s toys.
 Magnetic field: The space around a magnet or a current carrying wire within which a magnetic force is
experienced by another magnet is called magnetic field.
 Magnetic field lines: Magnetic field is represented by a series of curves around a magnet. They are
called field lines. They are lines drawn in a Magnetic field along which an imaginary north magnetic
pole moves.
Refer to figure 13.3 & 13.4 page no. 225 of N.C.E.R.T Text book)
 Properties of Magnetic field lines:
(i) They do not intersect each other.
(ii) It is taken by convention that magnetic field lines emerge from North Pole and merge at
the South Pole.
(iii) Inside the magnet, the direction of field lines is from South Pole to North Pole.
Therefore magnetic field lines are closed curves.
(iv) Closeness of field lines indicates stronger magnetic field.
(v) In weak magnetic field, they are widely spaced.
 Magnetic field lines due to a current through a straight conductor (wire) consist of series of concentric
circles whose direction is given by the Right hand thumb rule.
 Right hand thumb rule: If a current carrying straight conductor is held in your right hand such that the
thumb points towards the direction of current, then the wrapped fingers show the direction of
magnetic field lines.
(Refer to figure 13.7, page no. 228 of N.C.E.R.T Text book)
 Magnetic field line due to a current through a circular loop becomes straight line at the centre of the
loop.
 The strength of the magnetic field at the centre of the circular loop(coil)depends on:
(i) The radius of the coil-The strength of the magnetic field is inversely
proportional to the radius of the coil. If the radius increases, the magnetic
field strength at the centre decreases.
(ii) The number of turns in the coil: As the number of turns in the coil increase,
the magnetic strength at the centre increases, because the current in each
circular turn is having the same direction, thus the field due to each turn

57
adds up.
(iii) The strength of the current flowing in the coil: As the strength of the current
increases, the strength of the magnetic fields also increases.
 Solenoid: (Refer to figure 13.10, page no. 229 of N.C.E.R.T Text book)
(i) A coil of many turns of insulated copper wire wrapped in the shape of a cylinder is called a Solenoid.
(ii) Magnetic field produced by a Solenoid is similar to a bar magnet.
(iii) The strength of magnetic field is proportional to the number of turns & magnitude of current.
(iv) The strength of magnetic field inside a solenoid is uniform.
 Electromagnet: An electromagnet consists of a long coil of insulated copper wire wrapped on a soft
iron core.
 Fleming’s Left hand rule: Stretch the thumb, forefinger and middle finger of left hand such that they
are mutually perpendicular. Forefinger points in the direction of magnetic field and central finger in the
direction of current, then the thumb gives the direction of force acting on the conductor.
(Refer to figure13.13, page no. 231 13.13 of N.C.E.R.T Text book)
 Electric motor: A device that converts electric energy to mechanical energy.
 Principle of Electric motor: When a rectangular coil is placed in a magnetic field and a current is passed
through it, force acts on the coil, which rotates it continuously. With the rotation of the coil, the shaft
attached to it also rotates.
 Electromagnetic induction: The phenomenon of production of induced current in a closed circuit or
coil due to change in magnetic field is called Electromagnetic induction.
 Fleming’s Right hand rule: gives the direction of induced current.
Stretch the thumb, forefinger and middle finger of right hand such that they are mutually
perpendicular. Forefinger points in the direction of magnetic field, the thumb is in the
direction of motion of the conductor then the middle finger will give the direction of
induced current.
 Electric generator: A device that converts mechanical energy to electric energy.
Electric generator is of two types- (i) A.C generator (ii) D. C generator
 Principle of Electric generator: Electromagnetic induction
 Domestic electric circuits: (Refer to figure 13.20, page 238 of N.C.E.R.T Text book)
 We receive electric supply through mains supported through the poles or cables. In our houses we
receive AC electric power of 220V with a frequency of 50Hz.
The three wires in domestic electric circuit are as follows-
(i) Live wire- (Red insulated, Positive)
(ii) Neutral wire- (Black insulated, Negative)
(iii) Earth wire- (Green insulated) for safety measure to ensure that any leakage of current to a metallic body
does not give any serious shock to a user.

58
 Short circuit: is caused by touching of live wires and neutral wire
 Fuse: It is a protective device used for protecting the circuits from short circuiting and over loading
1. Magnetic field lines around a bar magnet.
2. Right hand thumb rule
3. Magnetic field lines through and around a current carrying solenoid.
4. An electromagnet.
5. A simple electric motor
6. Electric generator
1. Magnetic field lines around a bar magnet
2. Direction of electric current in a simple electric circuit.
3. Direction of Magnetic field lines depends on the direction of electric current.
.

59
MIND MAP
MAGNETIC
EFFECT OF
ELECTRIC
CURRENT
Safety measure
Fuse Earthing
Magnet and its
properties
Magnetic field lines &
properties.
Right hand thumb rule
Solenoid
Electromagnet
Fleming left hand
rule
Electric motor
Fleming’s right hand rule.
Electromagnetic induction.
Generator
Domestic electric
circuits

60
Q. PAPER FOR FORMATIVE ASSESSMENT
Instructions:
1. State two uses of electromagnet.
2. An electron is moving along X – axis in a magnetic field directed along Y – axis. In which direction
will the electron deflected.
3. State Fleming’s left hand rule.
4. What is the importance of earth wire?
5. Should a copper wire be used as a fuse wire? If not, why?
6. Give two points of difference between electromagnet and permanent magnet.
7. Draw the magnetic field lines indicating direction of the magnetic field through and around
i) A circular loop of wire carrying electric current.
ii) A solenoid carrying electric current.
8. What is magnetic field? State right hand thumb to know the direction of magnetic field at a point.
9. Give four features of domestic electric wiring.
10. Draw a schematic diagram of domestic wiring system and write its main features.
11. Match the following:
A B
i) Right hand thumb rule a) Force on a conductor in a magnetic field
ii) Fleming’s left hand rule b) Direction of magnetic field of straight
conductor
iii) Fleming’s right hand rule c) Direction of induced current in conductor
d) Polarity of any end of a solenoid.
12. a) Draw a labelled diagram to show how electromagnet is made.
b) What is the purpose of soft iron core in making electromagnet?
13. Write two differences between AC and DC current and draw diagram of them also.
14. a) Write principle of electric generator.
b) Explain construction and working of generator.
c) Draw labelled diagram of electric generator.
1. On what effect of an electric current does an electromagnet work?
A. Magnetic effect of electric current
2. What is the frequency of AC (Alternating Current) in India?
A. 50Hz
3. On what effect of an electric current does a fuse work?
A. Heating effect of electric current.

61
HOTS QUESTIONS (UNSOLVED)
1. Name the sources of direct current.
2. Why do two magnetic field lines never intersect each other?
3. What is the role of split ring in an electric motor?
4. What is an earth wire?
5. What modifications in commercial electric motor enhance the power of the motor?
ORAL QUESTIONS
1. a) What are magnets?
b) What are natural magnets?
c) What is the meaning of the word lodestone?
d) What is the origin of the word magnetism?
2.
a) What is the sure test of magnetism?
b) What happens if we break a magnet into two pieces?
c) Is it possible to obtain isolated north and south poles?
3. a) What is magnetic field line?
b) Can two magnetic field lines intersect? If not,Why?
c) Magnetic field lines are closed.Why?.
d) How do the field lines of the regions of strong field different from those of weak field?
4. a) What is a solenoid?
b) Is the magnetic field of a solenoid similar to that of a bar magnet?
c) State the two factors by which the strength of magnetic field inside a solenoid can be
increased.
d) How will you determine the direction of the magnetic field due to a current carrying
solenoid?
5. a) What is an electromagnet?
b) What is the effect of placing an iron core inside a solenoid?
c) What type of core should be used inside a solenoid to make an electromagnet?
d) Give two advantages of electromagnets.
ORAL QUESTIONS
1. What important observation did Oersted make in his experiments with current carrying
conductors?
2. How can you locate a current – carrying wire concealed in a wall?
3. A freely suspended magnet always points along north – south direction. Why?
4. What type of core should be used inside a solenoid to make an electromagnet?
5. What is the principle of an electric motor?
6. A generator converts energy from one form to another. Name these two forms of energy.
7. Which wire (live, neutral or earth) goes through the switch?
8. Are different appliances connected in series or parallel in a house?
9. What is the colour convention for live, neutral and earth wires?

62
VALUE BASED QUESTION:
1. ASHOK used a fuse rated as 5 A in a circuit in which an electric heater of 2 KW was connected
with the supply of 220V.The heater was not working as the fuse wire melted. Ashok discussed
the problem with his friend Ram. Ram suggested him to use a fuse rated 10 A in the circuit. The
problem was solved.
(i) What values are shown by Ram?
(ii) How much current was flowing in the circuit with the fuse 10A?
Ans; (i) Helpful; High degree of awareness.
(ii)I = P/V =2000/220 =9.09 A
..

63
CHAPTER-15
SOURCES OF ENERGY
 Characteristics of a good fuel:
(v) High calorific value
(vi) Less smoke
(vii) Less residue after burning
(viii) Easy availability
(ix) Inexpensive
(x) Easy to store and transport
 Fossil fuels: were formed millions of years ago, when plants and animal remains got buried under the
earth and were subjected to high temperature and pressure conditions. E.g.: Coal, Petroleum, etc.
These fossil fuels are non-renewable sources of energy and cause environmental problems due to
pollution.
 Thermal power plants:
(i) Use coal, petroleum and natural gas to produce thermal electricity.
(ii) Electricity transmission is very efficient.
(iii) The steam produced by burning the fossil fuels runs the turbine to produce electricity
 Hydro power plant:
(i) It is the most conventional renewable energy source obtained from water falling from a great
height.
(ii) It is clean &non-polluting source of energy.
(iii) Dams are constructed to collect water flowing in high altitude rivers. The stored water has a lot
of potential energy.
(iv) When water is allowed to fall from a height, potential energy changes to kinetic energy, which
rotates the turbines to produce electricity through EMI(Electromagnetic Induction)
 Disadvantages of Hydro power plant:
(i) Highly expensive to construct.
(ii) Dams cannot be constructed on all river sites.
(iii) Large areas of human habitation and agricultural fields get submerged.
(iv) People face social and environmental problems.
 Non-conventional sources:
(1) Bio mass:
o It is the source of the conventionally used fuels that are used in our
country. E.g.: Cow dung cakes, fire-wood, coal, charcoal
o Bio gas: It is a mixture of gases produced during decomposition of bio mass in the
absence of Oxygen. (Anaerobic Respiration). Methane is the major component of
bio gas.

64
o Bio gas plants: Animal dung, sewage, crop residues, vegetable wastes, poultry
droppings, etc. are used to produce Bio gas in Bio gas plants.
o Uses : Bio gas is used for cooking and lighting.
o (Refer to figure 14.4, page no. 247 of N.C.E.R.T Text book)
(2) Wind energy:
o It can be converted into mechanical and electrical energy.
o Kinetic energy of the wind is used in running of wind mills, which are used to lift
water, grind grains, etc.
o Wind mill-(Refer to figure 14.5, page no. 247 of N.C.E.R.T Text book)
o Advantages: (i) Eco friendly (ii) Renewable
o Disadvantages: (i) Wind speed not uniform always.
(ii) Needs a large area to erect series of wind mills.
(iii) Big amount of investment is needed.
(iv) Output is less as compared to investment
(3) Solar energy:
o Solar radiations can be converted into electricity through solar cells (photovoltaic
cells).
o Photovoltaic cells convert solar radiations directly into electricity through silicon
solar cells.
o Solar cells arrange on a large flat sheets form a solar panel.
o Solar cookers are painted black from outside and a large glass plate to trap solar
radiations by greenhouse effect.
o (Refer to figure 14.6, page no. 249 of N.C.E.R.T Text book)
o Advantages of Solar cookers:
(i) Eco friendly
(ii) Renewable
(iii) Used in rural areas.
(iv) Retains all the nutrients in food due to slow cooking.
o Disadvantages of solar cooker:
(i) Solar radiations are not uniform over earth’s surface.
(ii) Cannot be used at night or on cloudy days.
(iii) Cannot be used to make chapattis for frying as these
require a temperature of 1400
C or more.
(Maximum temperature of 1000
C only can be
achieved in a solar cooker)
o Other solar devices- Solar water heater, Solar furnace
(4) Geo thermal energy:
(i) Energy harnessed from the heat of the sun is called Geo thermal energy.
(ii) Magma is formed when this heat melts the rocks. The molten rocks and hot gases are
called magma
(iii) The magma gets collected at some depths below the earth’s surfaces. These places are
called ‘Hot spots”
(iv) When underground water comes in contact these hot spots, it changes into steam,
which can be used to generate electricity.
o Advantages of Geo thermal energy:
(i) Renewable
(ii) Inexpensive
o Disadvantages ofGeo thermal energy:

65
(i) Only few sites available for harnessing energy.
(ii) Expensive
(5) Nuclear energy:
(i) Energy released when some changes take place in the nucleus of the atom
of a substance, is called Nuclear energy.
(ii) It is used for heat generation, fuel for marine vessels.
o Advantages of Nuclear energy:
(i) Alternative source of energy due to depletion of fossil fuels.
(ii) From a small amount of fuel, a large amount of energy is released.
o Disadvantages of Nuclear energy:
(i) Risk of nuclear waste leakage
(ii) High cost of setting up of nuclear plant
(iii) Pollution of environment.
(6) Energy from the sea-
(A) Tidal energy: Locations in India – Gulf of Kutch, Gujrat& W. Bengal
(i) Depends upon harnessing the rise and fall of sea level due to tidal action.
(ii) Dams are constructed across a narrow part of sea and turbine converts tidal energy into
electrical energy.
Disadvantages: Uniform tidal action is not seen
(B) Wave energy:
(i) Kinetic energy of the waves of sea are used to rotate turbines..
(ii) These turbines generate electrical energy
1. Hydro power plant
2. Bio gas plant
3. A wind mill
4. A solar cooker

66
MIND MAP
Characteristics of good fuel
Fuel
Sources of energy
Renewable
Non renewable
Nuclear
Solar
Biomass
Water
Wind
Fossils fuels
coal
Petroleum
Thermal
power plant
Nuclear
power
plant
Solar
cooker
Biogas
plant
Hydro
power
plant
Wind
mill
Natural Gas
Geothermal
Hot Spots
Electricity

67
Q.PAPER
Instructions:
1. Name the component of sunlight, exposure to which may cause skin cancer.
2. Flowing water possess which type of energy.
3. Name one place in India where wind energy power station is installed.
4. What is a solar panel?
5. What type of energy transformation takes place during winding of spring of a clock?
6. Write two differences between renewable and non – renewable sources of energy.
7. What is the principle of solar cooker? Name two types of solar cooker.
8. Name any two types of harmful nuclear radiations emitted during nuclear fission.
9. What is thermal power plant? Where it is preferably situated?
10. What is the principle of solar cooker? Give two limitations and two advantages of solar cooker.
11. Name the fuel for hydro power plant. Mention two advantages and disadvantages of producing
electricity at the hydro power plant.
12. Explain why:
a) It is difficult to burn a piece of fresh wood from a tree.
b) Pouring dry sand over the fire extinguishes it.
c) It is difficult to use hydrogen as source of energy.
13. What are the different types of energies obtained from sea? Explain.
14. a) What is a principle of Biogas?
b) Explain it working in brief.
c) Draw a labelled diagram of biogas plant.
1. Name the materials used for making solar cells.
A. Silicon, Germanium and Selenium
2. What fraction of solar energy reaches the earth’s surface?
A. 47%
3. Name the process that produces a large amount of energy in the sun.
A. Nuclear fusion
4. Why is biogas called a clean fuel?
A. Because it- (i) leaves no ash (ii) does not cause pollution (iii) does not produce any
poisonous gas.
HOTS QUESTIONS (UNSOLVED)
1. What is the use of black painted surface in solar heating devises?
2. Why are bio gas plants considered to be boon to the farmers? Give reason.
3. Hydroelectricity generated at a dam may be considered another form of solar energy. Why?

68
4. How is the slurry left over after the generation of biogas in biogas plant used?
5. Why is charcoal considered to be a better fuel than wood?
6. Why a solar cooker cannot be used for frying or making chapattis?
7. In parabolic reflector type coolers, even temperature up to 1800
C- 2000
C can be attained. How?
8. Modern chulahs are more efficient than traditional chulahs. Why?
9. How is hydro energy converted into electrical energy?
10. Explain, why only a part of the solar energy that strikes the upper regions of atmosphere reaches the
surface of the earth?
ENERGY
ORAL QUESTIONS (CONVERSATION TYPE)
1. a) What is a good source of energy?
b) Name one good source of energy.
c) It is a renewable source of energy?
d) Is it conventional or non – conventional source of energy?
e) What other name is given to it?
f) What is a fossil fuel?
g) Name any other two fossil fuels.
2. a) Which is the ultimate source of all forms of energy?
b) Can you explain?
c) Name some renewable source of energy arising due to sun.
d) Name some non – renewable source of energy arising due to sun.
e) Why is the energy contained in fossil fuels considered due to sun’s energy?
f) Name any source of energy not influenced by sun’s energy.
3. a) What is the principle of nuclear energy?
b) What are the kinds of nuclear reaction?
c) Which of these can be used for destructive purposes?
d) Which of these can be used to produce energy for common use?
e) What is nuclear fission?
f) Name two substances which are easily fissionable.
g) What are these substances called?
h) What is this phenomenon of breaking up of radioactive isotopes called?
i) Name the rays emitted.
ORAL QUESTIONS
1. Which component of solar radiations produces heat?
2. Name a form of energy that can be harnessed from the oceans.
3. Name the main component of biogas.
4. Name a fuel which is considered cleaner than CNG.
5. What is common between an atom bomb and a nuclear reactor?
6. What is the main transformation of energy during working of a windmill?
7. What are the conditions to achieve nuclear fusion?
QUIZ
1. I am a force that cannot be created but my form may be changed.
2. I am an important part of the system that transforms that transforms K.E. / P.E. into electrical

69
energy.
3. I have been used to produce energy for a long time and my origin is in the remains of plants and
animals.
4. I used to thrown as a waste material for centuries. But I am given an honourable name and a
useful work to perform.
5. I have a huge body capable of eating water from any source with a decorative head called
Hydroelectric power station.
6. I resemble a fossil fuel but find use as self sustained source of energy especially in rural areas.
7. I produce a chain of reactions each step capable of producing tremendous amount of energy.
8. I am associated with nuclear reactions but deliver heat in critical conditions.
9. I am the lightest fuel with a large potential as a source of energy.
10. I deliver hot springs with taking any energy from man – made sources or sun.
1. In an IT firm there are 60 professionals, most of them come by their personal vehicle and from same
locality.
(a) will this practice of commuting help the nature? Justify it.
(b) if not what can they do to help the nature?
(c)what associated values will the learner get from the idea develop to help the nature?
2. a school organised the study tour for its students to observe, how do people in a village use energy
resources for their living>? They observed that in one of the village people use wood and cow dung as a
fuel . while in the nearby village they saw modern technology was used by the villagers for better
sanitation and management of their bio-waste and sewage materials by establishing biogas plant.
(a) if you compare the sanitation of both the villages which practice would you prefer to be the best and
why?
(b) state the associated values which you get from this excursion tour.

71
(Second Term)
Contents:
Nos:
1. Carbon and its compounds 89
2. Periodic classification of elements 97
3. How do organisms Reproduce 102
4. Heredity and evolution 105
5. Light-Reflection and refraction 110
6. The human eye and the colourful world 115
7. Management of natural resources 119
8. Our Environment 123
******

72
Topic 1: Carbon and its compounds
Important terms and conditions
Versatility of carbon :Carbon is known metal and occurs in free as well as combined state in nature.
Free state: Diamond ,graphite and coal.
Combined state :
1.Solid state: All animals and plants products.
2.Liquid state: Petroleum and vegetable oil .
3.Gaseous state: In air has CO 3 .
Carbon has 4 valance electrons carbon can form an anion C4-
by gain of electrons.It can also form of cations
C4+
by loss of electron.IT can share its valance electrons with other carbon atoms or atoms of non-metal and
forms covalent bonding.
Compounds of carbon: Simplest compounds of carbon are hydro carbon and simplest hydro carbon is
methane.
Classification of hydro carbon:
Saturated hydro carbon: Unsaturated hydro carbon:
(CnH2n+2)
Compounds having single bond compounds having double and triple bonds.
ALKANES ALKENES ALKYNES
CnH2n+2 CnH2n CnH2n-2
ethane (C2H6) Ethene C2H4 Ethyne C2H2
S. No. Hydro carbons Definitions Examples
1 Straight chain All carbons are in form of straight Butane

73
chain
2 Branched Chain One or more carbon atoms are
attached to main straight line
Isobutane.
3
a
b
Ring or cyclic
hydro carbon
Saturated
Unsaturated
Carbon atoms are bonded by
single covalent bond.
Carbon atoms are bonded by
doubled or triple covalent bond.
Cyclohexane.
Ethane
Ethene and
Ethyne
Isomerism:The phenomenon of existence of compounds in two or more forms with same molecular formula but
different structure.
Functional group: An atom or groups of atoms which makes a carbon compounds reactive and decide its
properties.
Sr.no. Hetro atoms Functional
groups
Formula of
functional
group
example
1. Cl/Br Halo-
chloro/bromo
-Cl,-Br Chloromethane(CH3Cl)
2. oxygen 1.Alochol
2.Aldehyde
3.Ketone
-OH
-CHO
>C=O
Ethanol
C2H5OH
Methanal
HCHO
Propanone

74
4.Carboxylic
acid
-COOH
CH3COCH3
Ethanoic acid
CH3COOH
HOMOLOGOUS SERIES:A series of compounds in which the same functional group substitude for hydrogen in a
carbon chain,such that successive compounds differ by CH2 groups e.g CH4 ,C2H6,C3H8 etc.
NOMENCLATURE OF CARBON COMPOUNDS:
Prefix word root+suffix+Functional group.
CARBON COMPOUNDS:
ETHANOL –C2H5OH common name ethyl alcohol
ETHANOIC ACID- CH3COOH.common name acetic acid.
ESTERIFICATION REACTION:The reaction between carboxylic acid and an alcohol in the presence of conc.
Sulphuric acid to form a sweet smelling substance ester. .e.g
Conc.H2SO4
CH3COOH+C2H5OH CH3COOC2H5+H2O
Saponification reaction : Alkaline hydrolysis of ester produces soaps.
Heat
CH3COOC2H5+NaOH CH3COONa+C2H5OH
Reaction with carbonates and hydrogen carbonates: reaction of ethanoic acid with carbonates or bi carbonate
evolves carbon dioxide gas.
2CH3COOH+Na2CO3 2CH3COONa+CO2+H2O

75
SOAP AND DETERGENT: Soap is sodium and potassium salt of long chain of carboxylic acid .They form lather with
soft water only.
Detergent are ammonium or sulphonate salts of long chain carboxylic acid .they even remain effective in hard
water and foam lather.
Cleansing action of soap

77
Summative Assessment 2
Carbon and its compounds
F.A-III
PAPER PEN TEST
TIME: 40 Min Max marks:40.
1. Name the compound form heating ethanol at 443 K with excess of conc.H2SO4. 1
2. What happened when a small piece of sodium is dropped into ethanol ? 1
3. Write the chemical equation for the decarboxylation of ethanoic acid? 1
4. Give an example of esterification reaction. 1
5. Name the product obtained when ethanol is oxidized by acidified potassium dichromate or
alkaline potassium permanganate. 1
6. why is conversion of ethanol to ethanoic acid is an oxidation reaction. 1
7. Name the 2 elements which are present both in CNG and Petroleum 2
8. Draw the electronic dot structure of ethane molecule (C2H6) 2
9. Write the IUPAC name of the next homologous of CH3OHCH2CH3. 2
10.Define homologous series of organic compounds series of organic compounds ,Mention any two
characteristics of homologous series. 2
11.Describe a chemical test to distinguish between ethanol and ethanoic acid. 2
12. Give the name of functional groups (i)-CHO (ii) >C=0 2
13.Why does carbon form compounds mainly by covalent bonding ? 2
14.what are the two properties of carbon which lead to huge number of carbon compounds we see around
us ? 2
15 Allotropy is a property shown by which class: substances elements compounds or mixtures? Give one
examples of allotropy. 2
16. How may be the following be obtained from ethanol ? Express giving chemical equations.
(i) Ethyl ethanoate (ii) Sodium ethoxide. 2
17. Describe with chemical equation how ethanoic acid may be obtained from.
(i) Ethanol (ii) Methanol 2
18. Explain the cleansing action of soap 3
19.Distinguish between esterification and saponification reactions of organic compounds 3
20. Explain the structure of graphite in term of bonding and give one property based on this
structure. 3
21. Name the organic acid present in vinegar .write a chemical equation which represents the
commercial method for the preparation of this acid from methanol. 3
HIGH ORDER THINKING SKILLS (HOTS) QUESTIONS:
1. Why the colour of potassium permanganate disappears, if it is added to warm solution of
ethanol.
2. An organic compound with molecular formula C2H4O2 produces brisk effervescence on
addition of sodium carbonate /bicarbonate.
a .Identify the organic compound.
b. Name the gas evolved.
c. How will you test the gas evolved.
d. Write the chemical equation for the above reaction.

78
e. List two important uses of the above compound.
3. a.What are the various possible structure formulae of a compound having molecular formula
C3H6O .
b. Also give the IUPAC names of the above possible compounds.
c.What is the similarity in these compounds?
4. A mixture of oxygen and ethyne is burnt for welding, can you tell why a mixture of ethyne
and air is not used.
5. Two carbon compound A and B have molecular formula C3H8 and C3H6 respectively. Which one of the
two is most likely to show addition .justify your answer .Explain with the help of a chemical equation,
how an addition reaction is used in vegetable ghee industry.
6.1ml glacial acetic acid and 1ml of ethanol are mixed together in a test tube. Few drops of concentrated
sulphuric acid is added in the mixture are warmed in a water bath for 5 min.
a. Name the resultant compound formed.
b. Represent the above change by a chemical equation .
c. What term is given to such a reaction.
d. What are the special characteristics of the compound formed.
7. An organic compound ‘X’ with a molecular formula C2H6O undergoes oxidation in the
presence of alkaline KMnO4 and forms the compound ‘Y’.
a. Identify ‘X’ and ‘Y’
b. Write your observation when the compound ‘X’ is made to react with compound ‘Y’
which is used as a preservative for pickles.
8.what is formalin ?
Topic 1:Carbon and its compounds
F.A-IV
QUIZ:
1.Name the simplest hydrocarbon..
2.What is the general formula of alkynes.?
3.Name the carboxylic acid used as preservation
4.Name the product other than water formed on burning of ethanol in air.
5 Give the IUPAC name of the following compounds.
i) An aldehyde derived from ethane.
ii) A ketone derived from butane.
iii) A chloride derived from propane.
iv) An alcohol derived from pentane.
Multiple choice questions
1. Dilute acetic acid was added to the four test tubes containing the following chemical.
i.KOH ii.NaHCO3 iii. K2CO3 iv. NaCI
Brisk effervescence was observed in test tubes

79
a) i & ii b) ii & iii c) i& iv d) ii & iii
2. Which of the following solution of acetic acid in water can be used as vinegar used in pickles?
a) 5-10% b. 10-15% c.20-130% d.100%
3.The suffix used for naming an aldehyde is
a..ol b.al c. one d..ene
4.When acetic acid reacts with ethyl alcohol ,we add cons,H2SO4,its acts as……….and the
process is called…………………..
a)Oxidizing agent, saponification. b). Dehydrating agent, esterification c). reducing agent ,esterification.
d).Acid & esterification.
5. 2ml of ethanoic acid was taken in each of the three test tubes. A,B and C and 2ml.4ml and 8ml water was
added to them ,respectively .A clear solution is obtained in:
a. Test tube A only.
b. Test tubes A & B only.
c. Test tubes B and C only.
d. All the test tubes.
6. 2 ml of acetic acid was added in drops to 5ml of water it was noticed that:
a. The acid formed a separate layer on the top of water.
b. Water formed a separate layer on the top of the acid.
c. A clear and homogenous solution was formed.
d. A pink and clear solution was formed.
7. A few drops of ethanoic acid was added to solid sodium carbonate .The observation made was that
a. A hissing sound was evolved
b. Brown fumes evolved.
c. Brisk effervescence occurred.
d. A pungent smelling gas evolved.
8. Acetic acid, when dissolved in water, it dissociates into ions reversibly because it is a :
a) Weak acid b) strong acid c) weak base. d) strong base.
9.Which of the following hydrocarbon can show isomerism?
a.C2H4 b. C2H6 c.C3H8 d.C4H10
10.Combustion of hydrocarbon is generally accompanied by evolution of
a. Heat b. Light c. both heat and light d. Electric current.
ACTIVITY :
1.To Study the saponification reaction for the preparation of soap in the laboratory using any vegetable oils.
2.Prepare soaps of different colours and fragrances.
CARBON AND ITS COMPOUNDS
3..Testing the hardness of water.
4..Collect information about artificial ripening of fruits by ethylene.
PROJECTS :
To prepare models of methane ,ethane,ethyne and benzene molecules using thermocols ,ball and match sticks.
TOPICS FOR DEBATE:
1.Role of esters in everyday life.
2. Condemning the use of alcohol as a social practice.
3.Use of biodegradable synthetic for cleansing purpose.

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TOPIC 2: PERIODIC CLASSIFICATION OF ELEMENTS
Gist of the lesson:
Classification of elements: the arrangement of element in such manner that element with similar properties
are grouped together while elements with dissimilar properties are separated.
Early attempt to classify elements:
DOBEREINER’S TRIADS:
He arranged the elements with similar properties in a group of three known as triad in such a manner that
the atomic mass of the middle element was approximately the average of the other two elements
LIMITATIONS:
Only three triads were identified from the element known at that time .hence this classification was not
useful.
NEWLAND’S LAW OF OCTAVES :
He arranged the element in the order of increasing atomic masses starting with hydrogen (least atomic
mass) and ended with thorium having atomic mass 56. According to him, the properties of every eighth
element are similar to the first element. It was compared to music notation sa,re ,ga ,ma, pa ,da ,ni ,sa and
thus the name Newlands law of octaves(notes of music ).
LIMITATIONS:
1. It was applicable only for lighter element having atomic mass upto 40 amu, i.e. up to calcium.
2. He believed that only 56 elements existed in nature but later on more element were discovered whose
properties did not fit into Newland law of octaves.
3. Some elements having different properties were grouped together like cobalt and nickel have been
placed with halogens .
Due to above limitations, Newland law of octave was rejected
MANDELEEV’S PERIODIC TABLE :
He arranged the elements in order of increasing atomic masses, similarity in physical and chemical
properties of element. Properties of hydrides and oxides of different element were studied and elements
with similar properties were grouped together.
He classified the elements in table consisted of vertical columns called groups and horizontal rows called
periods. There were 8 groups in table and group is subdivided into subgroups A and B except group VIII
which has three sets of elements in 4th, 5th, 6th period.
LIMITATIONS OF MENDELEEV, PERIODIC TABLE:
1. Position of hydrogen was not assigned correctly.
2. No separate position has been given to isotopes of an element.
3. Some element having higher atomic mass are placed before the elements with lower atomic mass.
MODERN PERIODIC TABLE:
Mosely modified the Mandelleve’s periodic table by taking atomic number as the fundamental property
instead of atomic mass.
Modern periodic table consists of 18 vertical columns known as group, and 7 horizontal rows known as
periods.

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GROUPS:
Elements in group one are called alkali metal s.
Elements in group 2 are called alkaline earth metals.
Elements in group 17 are called halogens.
Group 18 elements are called inert gasses or noble gases.
Significance of group in the periodic table is that an element in a group has same number of valance
electron, valency and thus identical chemical properties.
PERIODS
1ST PERIOD – 2 elments and is called very short period.
2nd PERIOD- 8 elements and are called short period.
3rd PERIOD – 8 elements and are called short period.
4th PERIOD – 18 elements and are called long period.
5th PERIOD – 18 elements and are called long period.
6th PERIOD – 32 elements and are called very long period.
7th PERIOD - incomplete period.
The number of shell present in the element indicates the period to which it belongs .
VALENCY :
It is defined as the combing capacity of an atom of an element to acquire noble gas configuration. it is equal
to the number of electron lost , gained or shared during the formation of chemical compound .
ATOMIC SIZE / ATOMIC RADII:
It is defined as the distance from the centre of the nucleus to the outer most cell of atom. it is generally
expressed in pico meter ( pm) .
On moving down the group the atomic radii increases.
Because on moving down the group a new energy shell is added which increases the distance between the
outermost electron and the nucleus. All though the nucleus charge also increases, but it is compensated by
the additional shell being added thus, increasing the size of the atom.
Across the period the atomic radii decrease. Due to the increase nuclear charge, the pull on the electron
increases and hence, they are pulled closer to the nucleus thus, decreasing the atomic size.
Oxides and its nature. Metal reacts with oxygen to form oxides by loss of electrons. These oxides on
dissolution in water from bases.
REACTIVITY OF ELEMENTS.
Down the group reactivity of metal increases as the tendency to lose electron increases due to the
increased atomic size .
Reactivity of non metals decreases down the group because of the increased atomic size and the tendency
to gain electron decreases.
On moving across the period the reactivity first increases due to the decreased in the metallic character and
increase in non-metallic character.

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PRACTICE QUESTIONS FOR FORMATIVE ASSESSMENT III
TIME: 1 HRS
M.M:30
Q.1what is the position of hydrogen in the modern periodic table? (1)
Q.2 where are the isotopes of the same elements having different atomic masses placed in the periodic
table ? (1)
Q.3 An element M is the third group of the periodic table. Write the formula of its oxide? (1)
Q.4 What is the valency of magnesium with atomic no. 12 and chlorine with atomic no. 17? (1)`
Q.5what is the difference in number of shell in magnesium and sulphur? (1)
Q.6 on the basis of electronic configuration , how will you select (1)
i)the terminating member in a period .
ii) the chemically similar elements .
Q.7Give reason as to why the atomic radii of elements increase in a group while moving from top to bottom
? (2)
Q.8 element in a group of periodic table have similar chemical properties why ? (2)
Q.9 explain why atomic number is more important than atomic weight in determining chemical properties ?
(2)
Q. 10 where in periodic table do we find :
i)elements classified as non metal .
ii) elements forming negative ions .
iii)elements with high melting points .
iv)elements forming positive ions . (2)
Q.11in a group reactivity of metals increases while those of non metals decreases. Explain.(2)
Q.12 elements in a group of periodic table have similar chemical properties why. (2)
Q.13 elements of group 18 are called zero group. Why? (2)
Q.14 Write the electronic configuration of atoms of
a) potassium (K) b)argon (Ar) c)lithium (li) d) fluorine (F) e) chlorine (Cl) (5)
Q.15 i) Why is potassium more reactive than lithium?
ii) Why is fluorine is more reactive than chlorine?
iii) Which is smaller in size Cl or Ar?
iv) Which is smaller in size Li or F ?
v) Which is more electronegative F or Cl?
Q.16 The atomic no. of an element is 17.
i) What is its valency?
ii) Whether it is a metal or non-metal?
iii) Whether it is bigger or smaller in size then an element of atomic no.18?
iv) What type of bonds it will form with elements of group 18?
v) How would its oxide behave with litmus solution? (5)

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HOTS QUESTIONS
Q.1 an element has two electron in its M shell:
i) Identify the element. ?
ii) What type of ion will it form?
iii) What will be the formula of its chloride?
iv) Predict the solubility of its chloride?
Q.2 which among the following elements whose atomic number are given below belong to the same period
? Give the reason
17, 10,20,12,19,15
Q.3 Element X with atomic 12 and element Y with atomic number 17 reacts with hydrogen to form hydrides
. Which of them is expected to have high melting points?
Q.4 why is position of hydrogen not justified in modern periodic table?
Q5. Give two limitations of Mendeleev’s periodic table.
Q6. Name two elements for which Mendeleev left space in his periodic table.
FORMATIVE ASSESSMENT IV
QUIZ
Q.1 Name the element with atomic number 12.
Q.2 Name a metal in making cans and a member of group14.
Q.3 Name the most electronegative element in the periodic table.
Q.4 Name the horizontal rows in the periodic table.
Q.5 On moving across the period, atomic size of the element increase or decrease.
Q.6 Who gave the classification on the basis of musical note.
Q.7 Name two elements belonging to group one which can be cut with the help of knife.
Q.8 What name is given to the elements belonging to group 2 of the periodic table and why?
Q.9 Name the lustrous non-metal having 7 valence electron .
Q.10 Name the highly reactive metal that give violet colour to flame.
Q.11 Name the gas used in coloured advertising lights having 2 valence electron .
DEBATE AND DISCUSSION
A) Drawbacks of Mendeleev’s and modern periodic table.
B) Achievements of Mendeleev’s and modern periodic table.
C) Advantages of modern periodic table in understanding chemistry.
PROJECTS
1 Power point Presentation on the following topics:
1. Modern Periodic Table based on the similarity of properties of elements
2. Contribution by various Scientists towards the development of Periodic Table.
3. PERIODIC CLASSIFICATION
a) Making flash cards to study atomic numbers electronic configuration and other properties of
elements.
b) Make an outline sketch of the Modern Periodic Table.
1. shivam helps his friend Rohan in studies. Shivam is topper in the class. Rohan also improved his performance.
They like each other and they are good friends.
(a)what values are proposed by Shivam?
(b)what type of bond exist between Rohan and Shivam?
(c )why are ionic bonds strong?

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HOW DO ORGANISMS REPRODUCE?
GIST OF THE LESSON
1) Reproduction: process by which living organism produce new individual of their own kind.
2) Creation of DNA copy: when the cell divides into two, each new cell gets a copy of each DNA
or chromosomes.
3) Importance of variation: variations are created by DNA copying mechanism during sexual
reproduction.
4) Asexual modes of reproduction:
a) Fission—binary & multiple fission
b) Fragmentation
c) Regeneration
d) Budding
e) Vegetative propagation
f) Spore formation
5) Sexual reproduction-
a) In flowering plant
b) In human beings
6) Parts of flowers
7) Pollination: self and cross pollination
8) Fertilization: male and female germ cell fuses to form zygote.
9) Puberty: The age, when reproductive organs become functional,(in female 10-12 years, in male
13-14 years).
10) Male reproductive system in human beings.
11) Female reproductive system in human beings.
12) Reproductive health-
a) To have awareness about STDs, (sexually transmitted disease).
b) Some common STDs are gonorrhea, syphilis & HIV-AIDS.
13) Contractive methods: to avoid pregnancy-
a) barrier method b) chemical methods c) surgical methods

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FORMATIVE ASSESSMENT-III
Very short answer type question:
Note: each question carries 1 mark.
1) What is reproduction?
2) Have you seen seeds of rose or potato? Name some plants whose seeds you may have seen.
3) Can an amoeba and hydra reproduce like human beings?
4) What changes are observed in the uterus if fertilization occurs?
5) Define fertilization?
Short answer type questions
Note: each question carries two marks:
1) In the human body, what is the role of (a) seminal vesicles (b) prostate gland?
2) State the difference between menarche and menopause?
3) What is variation? Mention the importance of DNA copying in reproduction.
HIGHER ORDER THINKING SKILLS(HOTS) QUESTIONS
1) Give two reasons for the appearance or variation among the progeny formed by sexual reproduction.
2) Colonies of yeast fail to multiply in water but multiply in sugar solution. Give one reason.
3) Malaria parasite divides into many daughter individual simultaneously through multiple fission. State an
advantage the parasite gets because of this type of reproduction.
4) What is the importance of DNA copying in reproduction?
5) How does reproduction help in providing stability to population of species?
6) Why is vegetative propagation practised for growing some types of plants?
7) Why would be the reason for adopting contraceptive methods ?
8) Name those parts of flower , which serve the same function as the following do in the animals a) testies b)
Eggs, c) Ovary ,d) Sperms.
*Activity- to grow rhizopus& prepare its temporary slide.
Aim: to show asexual reproduction in an organism.
App: slice of bread, water, box, slide, cover slip.
Procedure: children grow rhizopus on slice of bread and make a temporary slide.
*Project: 1.a) To study manner of vegetative reproduction in some commercially useful plants.
b) To study the seeds during sprouting period.
2. How do organisms reproduce.
1.Seprating the various parts of any 5 flowers displaying and comparing them.
2.Growing some plants by vegetative propagation.
*Seminars: reproductive health and sexually transmitted disease: children form groups and discus

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*Symposium: gender related problems: female infanticide.
*Group discussion: if there was no sexual reproduction…..
*Debate: is it necessary to learn about reproductive health from class VII?

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TOPIC 4: HEREDITY AND EVOLUTION
POINTS TO REMEMBER:
1.HEREDITY: Transmission of features or characters from one generation to another or from
parents to offspring through their genes
2.VARIATION: It occurs due to sexual reproduction, inaccuracies during DNA replication
(mutation) and due to environmental factors.
3.GENETICS: Branch of biology dealing with the study of heredity and variations.
4.ALLELES :There is one pair of alleles which can express itself whether present in homozygous
state or heterozygous state. Eg – T (tallness in pea plant), R(round seeds in pea
plant)
5.GREGOR JOHANN MENDEL:- (1822-1884): He is known as the father of ‘genetics’. He
worked on Sweet pea plant(pisumsativum).
6.GENOTYPE: genetic composition of an individual, eg – pure tall-TT, hybrid tall-Tt
7.PHENOTYPE: Visible traits of an individual. Eg – Tallness or Dwarfness.
8.EVOLUTION: gradual changes in traits of organisms from pre existing organisms is called
evolution.
9.SPECIATION: It may take place when variation is combined with geographical isolation.
(Formation of new species)

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FORMATIVE ASSESSMENT –III
TICK THE CORRECT OPTION:
1.The number of chromosomes in human ovum is
a.21 b.22 c.23 d.24
2. An example of homologous organs is
a.our arm and a dog’s foreleg b./our teeth and an elephant’s tusk
c.potato and runners of grass. d. all of these.
3. The hereditary units are:
a. Segments of RNA b. Genes. c. Chromosomes d. Chromatin
4. The science dealing with biotechnology is called.
a.Heredity and variation b. paleontology c. genetics d. Genetic engineering
HOTS
1.If a trait exists in 10% of a population of an asexually reproducing species and a trait B in 60% of
the same population which trait is likely to have arisen earlier?
2.Which of the following is not the example of artificial selection ?
A)Colours of rose b.Flavours of mangoes 3.colours of beetle 4.Starch quality of wheat.
3. Explain how advantages variations like long neck help an organism like Giraffe to survive
better?
4. Which of the following is the clearly acquired trait in human beings?
a.Intelligence b.Height C.Swimming d. Skin colour.
5. Why are human beings, who look different from each other size and colour belongs to the same species?
6. Acquired characters are not inherited .Give reasons.
7. All the human races like Africans, Asians ,European and others might have from common ancestors
provide few evidence in support of the view.
8. How is genetic drift different from natural selection? From the diagram given below which case shows natural
selection?
Refer to diagram 9.7 ,page 147 of textbook.

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Observe the diagram properly, mention the ratio of round, yellow seeds and wrinkled, green
seeds.
Refer to diagram 9.5,page 145 of text book.
9. From the figures given below ,make a pair of homologous and analogous organs.Also justify the answer.
Refer to page 132, diagram 9.8.of text book.
FORMATIVE ASSESSMENT –IV
QUIZ
A. Decomposers are also called __________
B. Producers prepare their _____________
C. Ozone layer is destroyed by ___________
D. Ecology is the study of the interaction of_________ with each other and their surroundings.
SEMINAR
A. Mendel’s work
B. Sex determination in organisms
C. Role play
D. Student in act as Aristotle ,Darwin,Lemark and Mendel
and present the work done by these great people.

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GROUP DISCUSSION
If Mendel had met!
Projects: 1. Save Tiger….. Children collect information about the Tigers from various national
Parks and Wild life sanctuaries. Perform the stage shows to develop the awareness about the
forests and wild life.
3. To collect information on artificial selection carried out in some crops and animals . Visit to
Vetenarycollege.
4. Visit to an agricultural research Institute to understand the various techniques involved in
Hybridisation.
5. 1.Conducting a survey on
A. Evolution of wisdom teeth in parents.
B. Free and attached earlobes.
C. Rolling of tongue.
D. Finger prints.
Debate: Use of Biotechnology in Human Welfare .
Activity; To study vestigial organs in Human beings . Students define vestigial
organs and discuss the use of every part of the body.Then come to the conclusion.

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CHAPTER :5 REFLECTION AND REFRACTION
Key concepts and terms:
1) Light: light is a form of energy. It brings the sensation of sight. It is a form of electromagnetic radiation. It also
provides us means of communication (Fiber-optics).
2) Light wave: light wave travels with a speed of 3 x 108
ms-1
in free space. Its speed depends on the medium.
3) Ray and beam: the straight line indicating the path of the light (arrow- direction is called a ray. A bundle of
rays originating from the same source of light in a particular direction is called a beam of light.
4) Reflection: when light falls on a surface and gets back the same medium, it is called reflection.
5) Image: the point of convergence or the point form where the light appears to diverge after reflection or
refraction is called image.
6) Angle of incidence: the angle between the incident ray and the normal at the point of incidence is called
angle of incidence.
7) Angle of reflection: the angle between the reflected ray and the normal at the point of reflection is called
angle of reflection.
8) Laws of reflection: 1) the incidence ray the reflected ray and the normal at the point of incidence, all lie in the
same plane.
2) The angle of reflection and the angle of incidence are equal.
9) Aperture: the width of the reflecting surface is called aperture.
10)Focus: the point on the principle axis where all parallel rays meet after reflection is called principle focus.
11) focal length: the length or separation between the pole and the focus is called focal length (PF = f)
12) In order to draw ray diagram, two rules are used:
1) The rays of light passing parallel to the principle axis will coverage at the focus after reflection.
2) The rays of light passing through the focus will emerge parallel to the principle axis after reflection.
3) The rays of light passing through the center of curvature will all retrace their both after reflection.(as it is
normal at the point of incidence)
4) The rays of light falling at the pole get reflected at the same angle on the other side of principle axis.(Laws of
reflection)
13) Relation between radius of curvature and focal length It is two times the focal length i.e. R=2f.
14) Mirror formula: 1/f= 1/v +1/u where f, v and u are the focal length, image distance and object distance.
15) Lens formula: if u, v and f are the object distance, image distance and focal length respectively then 1/f=1/v-
1/u
16) Magnification of a lens: m= size of image (h1)/ size of object (h0) also m= (h1)/ (h0) = v/u.
17. Magnification of a mirror : m = - = (h1)/ (h0)
18. Power of the lens is defined as the reciprocal of its focal length. P=1/f, Unit-Dioptre(D);
1D is the power of the lens whose focal length is 1 metre.

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(Pen Paper Test)
1) If the speed of light in a medium id 2 x 108
m/s, then its refractive index is:
a) 1 b) 10 cm c) 1.5 d) 0.5
2) The power of sunglasses is
a) 20 D b) 10cm c) 25cm d) zero
3) The refractive index of diamond is 2.42. What is the meaning of this statement in relation to the speed
of light?
4) Draw a ray diagram and show the image formed by a concave mirror when the object is kept at focus.
5) An object is placed at a distance of 10cm in front of convex mirror of focal length 15cm. find the nature
and position of image.
6) 1) Two thin lenses of power +3.5D and -2.5 D are placed in contact. Find the power & focal length of
lens combination?
1) Define 1) Snell’s law of refraction of light. 2) Pole of a concave mirror.
7) An object of size 4cm is kept at a distance of 20cm from the optical center of a converging lens of a focal
length 10cm. calculate the distance of image from the lens and the size of the image.
8) a) Define magnification. Write the sign convention used for expressing it.
b) Using lens formulae, find the position of image, its nature and magnification formed by a
concave lens of focal length 20cm and the object is at 15cm.
1) QUIZ:
1) Name the place where image is formed in the eye?
2) Name the muscular diaphragm that controls the size of the pupil?
3) What is the cause of dispersion of light?
4) Which color has got more wave length?
5) How many colors evolve when white light disperses?
6) What is the reason for the different deviation?
7) Who discovered that white light consists of seven colours?
8) What makes bees respond the ultraviolet light?
Oral questions:
1) What is a ray?
2) A Lemmon placed in water appears larger in size due to _______________
3) What does the negative sign of magnification of a mirror indicate?
4) What is the relation between focal length and radius of curvature of a spherical
mirror?
5) What is the range of vision of normal human eye?
6) What do you mean by lateral displacement?
7) Magnification produced by convex mirror for object of size 5cm is ½ what is the size
of image?

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8) What is the real image?
9) A ray of light strikes at 45 degree on a mirror. what is a angle of incidence and
reflection?
10) What is power of accommodation?
Home assignment:
1.What do you mean by Power of the lens?
2.What is the lens formula? Write the sign convention for various mirror and lens.
3.Name the lens/ mirror in the following situations;
i) Rear View mirror ii) magnifying Glass iii) Mirror with Dentist iv) Correction of Myopia .
4. The power of the lens is -2D .What is the focal length and nature of the lens?
Project Work ;
1.To find the focal length of the given concave mirror using candle light.
2.Study the phenomena of refraction of light in different medium( Glass slab, Plastic, etc)

99
MIND MAP
REFRACTION; Deviation in the path of
light when light travels from one
medium to the other.
Refraction occurs as
the speed of light is
different in different
medium.
Snell’s law of refraction.
n= sin i/ sin r
_________
i-Angle of incidence
r-Angle of refraction
Lesser the refractive index ;the medium is
optically rarer
Greater the refractive index :the medium is
denser.
Ref.index= speed of light in Vacuum/ speed of
light in medium. n= c/v
Optical density is the ability of
the lens to bend light either
towards or away from the
normal
Refraction by
spherical Lenses
1. Convex and
Concave lens
Convex lens forms real and
virtual image . The real image is
diminished, same size and
enlarged depending on the
distance u.( u>2f; u=2f; u<2f)
The virtual image is formed
when u< f.
Concave lens always
forms Virtual image and
demised image.
Len’s Formula: 1/v-1/u=1/f
Magnification=v/u
Power of a lens=1/f where f is
in metre.
Unit of Power=Dioptre.

100
THE HUMAN EYE AND THE COLOURFUL WORLD
Key concepts and terms:
1. Eye : The natural optical device using which man can see objects around him. It forms an inverted,
real image on a light sensitive surface called the retina.
Refer to NCERT figure 11.1 page no. 187
2. Power of accommodation: The maximum variation in power of the lens so that the far off and near by objects
are viewed is called power of accommodation.
3. Near point of eye : The minimum distance between the object and the eye so that a clear image is formed on
the retina. This distance is 25 cm.
4. Far point of Eye : The farthest point upto which the eye can see objects clearly is called the far point of the
eye. It is infinity for normal eye.
5. Persistence of vision: The time for which the impression or sensation continues in the eye is called the
persistence of vision. It is about 1/16th
of a second.
6. Myopia or short sightedness : Inability of the eye in viewing long distance objects. It is caused due to : i)
excessive curvature in the eye lensii) elongation of eye ball. It is corrected by using concave lens.
7. Hypermetropiaor long-sightedness: The inability of the eye in viewing the nearby objects. It is caused due to i)
greater focal length of the lens ii) eyeball becoming smaller. It is corrected by using convex lens.
8. Presbyopia: In human eye, with age, the near point recedes and the far point get reduced. The eye becomes
both myopic and hypermetric. This is caused due to i) weakening of cilliary muscles and ii) reducing ability of
the lens to change the curvature. It can be corrected by using bifocal lens.
9. Dispersion : The process of splitting of white light in to its seven constituting colours is called dispersion. The
band of seven colours is called spectrum of visible light.
- Rainbow is a natural spectrum which is caused by dispersion of sunlight by tiny water droplets, present
in the atmosphere.
10. Atmospheric refraction : The optical density of our atmosphere decreases with altitude. Thus a ray of light
entering any layer of the atmosphere suffers refraction as it travels through the other layers. This is called
atmospheric refraction. Natural phenomena which occur due to atmospheric refraction are – a) twinkling of
stars b) Advance sunrise and delayed sunset
11. Scattering of light : The earth’s atmosphere consists of gases and many kinds of particles. When light falls on
such particles it get scattered in all directions. Smaller particles scatter blue light to a larger extent than the red
light. Natural phenomena which occur due to scattering of light are - i) blue colour of sky b) Reddening
of the sun at sunrise and sunset.

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Give reason for the following:
1) Red light is used for danger signal
2) Cause of Colour blindness.
3) Sky appears black in Moon.
4) Rainbow is seen on a rainy day in the presence of sunlight.
4) A person with a myopia eye cannot see objects beyond a distance of 1.5m. What would be the
power of corrective lens? Which type of lens is used?
5) What do you understand by myopia? Write two causes of it?
6) What do you mean by far point and near point of eye?
7) What is presbyopia? State the cause of it and how is it corrected?
8) Explain: 1) why does sky look blue on a clear day
2) Twinkling of stars.
9) What is hypermetropia? State two causes of hypermetropia with help of ray diagrams.
.
HOTS
1.Why does it takes sometimes to see in a dim room when you enter the room from bright sunlight outside?
ANS: In the bright iris causes the pupil to become smaller so that only a small portion of light enter the eye
and rods of the retina are also adjusted in the same way. but when a person enter in to dim lighteach iris
takes sometimes to increase the diameter of the pupil so that more amount of light can enter the eyes to
see the objects clearly and rods of the retina also takes some time to adjust –themselves to get the picture
of the object in the dim light.
2Can we see a rainbow on the moon?
ANS:No, since there is no atmosphere on the moon.
3.Does a beam of light give a spectum on passing through a hollow prism?
ANS:No,this is because dispersion of light cannot occur through a hollow prism containing air.
QUIZ: A
1. Name the place where image is formed in the eye?
2. Name the muscular diaphragm that controls the size of the pupil.
3. What is the cause of dispersion of light?
4. Give the cause of cataract of eye.
5. Which color has got more wavelength?
6. What makes bees respond to ultraviolet light?
Quiz:B

103
1) What is the focal length of a plane mirror?
2) Which of the two has a great power, a lens of shot focal lenth or a lens of large length?
3) What does m= +1 stand for?
4) What is the power of a lens if its focal lenth is 50cm?
5) What is the nature of image at retina?
6) Name the point inside the lens through which a ray of light goes deviated?
7) What is the S.I. unit of power of a lens?
Home Assignment
1. Name the photographic film equivalent to our eye .
2.Why does a glass slab not disperse white light?
3.Why do we not perceive the depth of a lake ?
4.Name two causes of Myopia, Hypermetropia and presbiopia.
5.Name the liquids that keep our eye soft.
6.What causes rainbow formation?
7.What is Mirage?
Project work:
1) To understand the dispersion of light with help of activity?
(Hint: materials, an irregularly shaped glass, white screen).
2) List, observe, reason and explain three cases of nature where dispersion happens.
(hint: 1) Sun rise and sun set 2.Formation of rainbow.3.Twinkling of stars)
3) Draw a labeled diagram of human eye and explain the function of retina, cornea, pupil, rods, and
cones?
seminar: (students will be divided into groups 7 they will present papers on the topic)
*Topic- PROBLEMS OF VISION:
2) Means to overcome and Corrective measure

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Topic 7: Management of natural resources
GIST
1) Natural resources: it is stock of the nature such as air, water, soil, minerals, coal, petroleum,
forest and wildlife that are useful to mankind in many ways.
2) Pollution: it is defined as the undesirable change in physical, chemical or biological
characteristics of our soil, air or water, which harmfully affect human lives or the lives of
other species.
3) pH of water: pH stands for ‘potential of hydrogen’. The acidic and basic character of
aqueous solutions can be described in terms of hydrogen ion and hydroxyl ion concentration
a pH below 7 indicates an acid solution and above 7 indicates an alkaline solution.
4) Three R’s to save the Environment: We can reduce pressure on the environment by applying
the maxim to ‘Reduce, Recycle and Reuse’ in our lives.
5) Sustainable Development: It is the development which can be maintained for a long time
without undue damage to the environment.
6) Need to manage our Resources: Our natural resources are limited. With the rapid increase in
human population, due to improvement in health care, the demand for all resources is also
increasing.
7) Biodiversity: It is the existence of a wide variety of species of plants, animals and
microorganisms in a natural habitats with in a particular environment or of genetic variation
with a species.
8) Wildlife: It means all those naturally occurring animals, plants and their species which are
not cultivated, domesticated and tamed.
9) Water harvesting: It means capturing rainwater where it falls or capturing the run off in a
local area and taking measures to keep the water clean by not allowing polluting activities to
take place.
10) Fossil Fuels: These fuels are obtained from the remains of plants and animals, which got
buried beneath the earth millions of years ago, changed into coal, petroleum and natural gas
due to excessive heat and high pressure inside the earth.
11) Coal: It contains chiefly carbon and its compounds mainly nitrogen, oxygen, sulphur and
hydrogen. It also contains inorganic matter.
12) Non-renewable Energy Sources: These are energy sources which cannot be replaced easily
when they get exhausted and are also called conventional sources of energy. E.g.: Fossil
fuels.
13) Uses of Fossil Fuels:
Coal: Thermal power plants and steam engines
Petroleum: Petroleum products like petrol and diesel are used as means of transport.
14) Management of Fossil fuels: The natural gas is a good alternative to fossil fuels like coal
and petroleum. The use of alternative source of non- conventional source of energy such as
solar energy, wind energy, biomass energy etc. Should be promoted to save the reserves of
fossil fuels .biogas can also be used for various purposes.
MIND MAP

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(paper pen test)
Q 1.i)Which one of the following started chipko movement 1
a.A.K.Banerjee b. Amrita Devi Bishnoi c.SundarLalBahugunad. Medhapatekar.
ii. From the list given pick the item that is not a natural resource?
a.soil b. water c. air d. Electricity
iii. The pH range most conductive for life of fresh water plants and animals is 1
a. 6.5-7.5 b.2.0-3.5 c.3.5-5.0 d.9.0-10.5
Q.2 What are renewable resources? How are they different from non-renewableresources 2
Q3 What would be the advantages of exploring resources and long term aim 2
Q4. Why should there be equitable distribution of resources 2
Q5 why are coal and petroleum known as fossil fuels? Why do we need to conserve them? 3
Q 6. Name the three “Rs” to save the environment?explain how each of them is beneficial for mankind?
Q7. Who are the stakeholders in forest? Why do we think so?
HOTS
1. What do you mean by Bio-Reserves? What are their objectives?
2.Explain the main points of difference between Agro Forestry and Urban Forestry Programme.
3.Beutiful Landscapes are of great value to Human Beings. Explain.

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QUIZ
1. ChipkoAndolan originated in
a. Kerala b. Rajasthan
c. Uttarakhand d. Karnataka
2. Kulhs are irrigation Canals of
a. Rajasthan b. Karnataka
c. Himachal Pradesh d. Assam
3. Which of the following is greenhouse gas?
a. Sulphurdioxide b. Carbon monoxide
c. Carbondioxide d. Nitrogen dioxide
4. Which of the following bacteria is found in Gangawater?
a. Coliform bacteria b. Streptococcus bacteria
c. Staphylococcus bacteria d. Diplococcus bacteria
5. Stake holders of forest resources in India are
a. Local people and industries b. NGO
c. Forest enthusiasts d. All of these
6. Arabari forest of Bengal is dominated by
a. Teak b. Sal
c. Bamboo d. Mangrove
7.Whichof the following are to be mangaged for sustainable developments?
a.Industriesb.ForestC.Cropsd.Resources
8.Red data book provides a list of :
a.Protect animals b. Rear animals for milk c.Entrap animal d.Both a & b
9.Sardarsarover dam is situated on river
a.Gangab.Narmada c. Yamuna d. Godavari
10. PynesSystem of irrigation is common in:
a.Biharb.Madhya Pradesh c. Rajastan d. Himachal Pradesh
Debate:
Topic “Money spent on protection of wild life should actually be spent for the welfare of poor people”
Seminar :
Reading papers by the students on the following topics:
i.River water pollution –source and solution
ii. Sustainable development
Symposium
i.Global warming and melting Himalaya –a controversy”
ii Save the tiger.
Home Assignment
1.Making a model to show Rainwater Harvesting.
2.Carry out a survey in your locality where Rainwater is being harvested.
3.Record the mode of transport used by your classmates.
4.Find out the amount of diesel/petrol used by families of your classmates.
5.Checking the PH of water from various sources.

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Topic 8 OUR ENVIRONMENT
GIST
1. ECOLOGY – The study of the interaction of living organisms with each other and their
surrounding is called ecology.
2. ENVIRONMENT –Everything that surrounds organisms and influences its life.
a) Biotic components of environment – The living organisms e.g. Plants and animals.
b) Abiotic components of environment –the nonliving components like air, light, etc.
3. ECOSYSTEM – All interacting organism in area =together with the nonliving constituents of
environment. ( Functional unit of an environment)
4. PRODUCERS – They make the energy from sunlight available to the rest of the ecosystem.
5. CONSUMERS – Living beings which depend on other sources for food are called consumers.
6. BIODEGRADABLE – Substances that are broken down by the action of bacteria or
saprophytes. e. g. Paper.
7. NONBIODEGRADABLE- Substances that are not broken down by the action of bacteria or
saprophytes. e.g. Plastic.
8. FOOD CHAIN – The process of transfer of energy from one organism to the other organism by
the process of eating and being eaten.
GRASS  GRASSHOPPER  FROG  SNAKE
9. FOODWEB --- It is a network of food links between populations in a community.
10. 10% LAW OF ENERGY FLOW – The energy available at any trophic level in a food chain is
10% of the previous one. It was given by Scientist Lindmann.
11. BIOLOGICAL MAGNIFICATION – Progressive accumulation of non-biodegradable waste at
various trophic levels of food chain.

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HIGHER ORDER THINKIN SKIILS (HOTS) QUESTIONS
1. Write any two ways of energy flow through an ecosystem.
2. Differentiate between biodegradable and non biodegradable with respect to the effect of
biological processes on them and the way they affect our environment.
3. Which level shows the maximum biological magnification? Why?
4. Why is pond self-sustaining unit while an aquarium may not be? Justify the answer.
5. Arrange grasshopper, frog, grass, eagle and snake in the form of food chain.
6. If 1000 KJ energy is available at producer level, how much energy will be available at first
carnival level?
7. Why do most food chains have 3-5 steps only?
8. Select the biodegradable items from the list given blow-
Polythene bags, old clothes, wilted flowers, pencil shavings, glass bangles, bronze statue,
vegetable peels.
9. What will be impact on ecosystem if bacteria and fungi are removed from the Environment?
10. Express your feelings on the picture given down below. What will happen if allCarnivores are
eliminated from the environment? What measures will you take to save Tiger?

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FORMATIVE ASSESSEMENT - III
Very short answer questions:
NOTE: Each question carries one mark.
TICK THE CORRECT OPTIONS:-
1. Ozone layer is destroyed by
a) SO2 b) Smog c) CFCs d) CO2
2. Which of the following is biodegradable?
a) Cow dung b) Plastic c) DDT d) Radioactive wastes
3. Vegetables peels, waste paper, wood carvings and egg shells can be used to make
a) Bricks b) Compost c) Urea d) None of these
4. Which of the following is constituent of food chain?
a) Grass, wheat and mango b) Grass, goat and human
c) Goat, cow and elephant d) Grass, fish and goat
5. Acid rain is caused by precipitation of
a) Oxides of sulphur b) CFCs c) Ozone d) CO2
SHORT ANSWER QUESTIONS:
EACH QUESTION CARRRIES TWO MARKS:
1) Classify the followings as decomposers and producers Green plants, bacteria, fungi,
algae, blue green algae.
2) Distinguish between producers and consumers.
3) Name two environment friendly practices.
ANSWER THE FOLLOWING QUESTIONS:
EACH QUESTION CARRIES THREE MARKS
1. How is ozone depletion caused? Name the compounds causing it.

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2. What is meant by biodegradable waste? Which of the following are biodegradable?
Agriculture residue, plastic, insecticides, sewage.
3. What is being done to avoid ozone depletion? ( Three steps)
4. What is meant by a trophic level? Why do we have a greater number of organisms at
lower levels?
Long answer (5 marks)
5. Describe any five modes of disposal of wastes.
FORMATIVE ASSESSMENT – IV
Quiz:
1. Ozone layer is destroyed by __________________.
2. Ecology is the study of the interaction of _______ with each other and their surroundings.
3. Decomposers are also called ________________.
4. Water, air, light and temperature are the examples of _______components.
5. Consumers ________ manufacture their own food and depend on plants and other animals for
their feed.
 Seminar: Children discuss ways and means to reduce the problems given below:
a) Ozone depletion b) Garbage disposal
 Symposium:
Environment problems: Groups mention the problems they are facing in day today life.
 Group discussion
Role of students in bringing awareness among community members on ill effects of polythene bags.
 Activities:
a) To study the ill effects of using some chemical like CFCs, nitrogenous fertilizers, DDT etc.
b) Field trips: Visit to a botanical garden.
1.Role play of food chain and food web by class students.
2.Skit /Action Song on Banning of plastics.
3.Write a passage on ‘Autobiography of plastics.
1. Plastic production is increasing day by day inspite of the fact that plastic is harmful for the
environment. Based on the above statement answer the following:
(a) what are the harmful effects of plastic usage?
(b) what are the alternatives that we can use instead of plastics?
(c) what value will you get from this passage ?
2. my sister is in habit of keeping the tap open while brushing her teeth. She loves to bath under
shower. My neighbour uses hose pipe attached to drinking water supply pipe for washing his scooter
and car. According to me their way of handling the most precious resource water in absolutely wrong.
On the basis of the above information answer the following question:
(a) do you agree with me or not?
(b)what changes in the above situation can be done to conserve water.
(c)what values are promoted by me?

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References :
Science - Textbook for class IX - NCERT Publication
Science - Textbook for class X - NCERT Publication
Assessment of Practical Skills in Science - Class IX - CBSE Publication
Assessment of Practical Skills in Science - Class X - CBSE Publication
Laboratory Manual Science - Class X , NCERT Publication

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sample
SUMMATIVE ASSESSMENT –I
SCIENCE (Theory)
Class – X
Time allowed: 3 hours Maximum Marks: 90
General Instructions:
a)All questions are compulsory.
b)The question paper comprises of two sections, A and B. You are to attempt both the sections.
c)Questions 1 to 3 in section A are one mark questions. These are to be answered in one word or in one sentence.
d)Questions 4 to 6 in section A are two marks questions. These are to be answered in about 30 words each.
e)Questions 7 to 18 in section A are three marks questions. These are to be answered in about 50 words each.
f)Questions 19 to 24 in section A are five marks questions. These are to be answered in about 70 words each.
g)Questions 25 to 27 in section B are 2 marks questions and Questions 28 to 36 are multiple choice questions based on
practical skills. Each question of multiple choice questions is a one mark question. You are to select one most appropriate
response out of the four provided to you.
Section A
1.Define Electrolysis.
2.What is breathing?
3.A wire of resistance 10Ω is bent in the form of a closed circle. What is the effective resistance between the two points at the
ends of any diameter of the circle?
4.A calcium compound which is a yellowish white powder is used as a disinfectant and also in textile industry. Name the
compound. Which gas is released when this compound is left exposed to air?
5.Name the ovarian hormones and give the function of any one of them.
6.What is the difference between direct and alternating currents? Write one important
advantage of using alternating current.
7.Balance the chemical equation:
(a)HNO3 + Ca(OH)2 Ca(NO3)2 +H2O
(b) NaOH + H2SO4 Na2SO4 + H2O
(c) NaCl + AgNO3 Ag Cl + NaNO3
(d) BaCl2 + H2SO4 BaSO4 + HCl
8.Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
9.(i) Differentiate between ‘strong’ and ‘weak’ electrolyte.
(ii) Select the strong electrolytes from amongst the following:
Molten NaCl, glacial acetic acid, strong ammonium solution, dil. HCl
10.Give reasons:
(a)Germanium is called a metalloid.
(b)Zirconium is known as a strategic metal.
(c)Nitrogen in used to preserve food.
11.(a) What are strategic metals? Give one example also.
(b) State the reason for the following behaviour of Zinc metal: On placing a piece of Zinc metal in a solution of mercuric
chloride, it acquires a shining silvery surface but when it is placed in a solutionof magnesium sulphate no change is observed.
12.What is the function of epiglottis in man? Draw a labelled diagram showing the human respiratory system.
13.Draw a diagram of the front view of human heart andlabel any six parts including at least two, that are concerned with
arterial blood supply to the heart muscles.
14.Draw the diagram of a neuron.
15.In a household 5 tubelights of 40 W each are used for 5 hours and an electric press of 500 W for 4 hours everyday.
Calculate the total electrical energy consumed by the tubelights and press in a month of 30 days.

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16.Aslam is a welder by profession who was working at Mohan’s house. After making a ‘railing’ by using electric welding
with naked eyes, Aslam was u
sing a grinder on it to smoothen the welding joints. Just them some particles fell into
Aslam’s eye. He started crying with pain. Mohan hired an auto and took him to an eye hospital, doctor used a device
connected to two electric wires to remove the particles form Aslam’seye. Aslam asked Mohan what had fallen into his eye
and what device was used by the doctor to remove that particle from the eye. Being a science student of class X, Mohan
explained everything to Aslam and asked him to be careful in future.
Read the above passage and answer the following questions:
(a)What could be the particle fell into Aslam’s eye?
(b)What device was used by the doctor to remove the particle and how it worked?
(c)What values are shown by Mohan during this episode?
[Value Based Question]
17.Explain the difference between nuclear fission and nuclear fusion reaction with examples. Give reason why the energy due
to fusion is not being used to meet our day to day energy needs?
18.With the help of a labelled diagram, describe the working of a solar water heater.
19.With the help of an activity, explain that hydrogenand oxygen are released when electric current is passed through water.
Or
(a) Crystal of copper sulphate are heated in a testtube for some time:
(i)What is the colour of copper sulphate crystals befo
re heating and after heating?
(ii)What is the source of liquid droplets seen on the inner upper side of the test tube during the heating process?
(b) A metal ‘X’ when dipped in aqueous solution of aluminium sulphate no reaction is observed whereas when it is dipped in
an aqueous solution offerrous sulphate, the pale green solution turns colourless. Identify the metal ‘X’ with reason.
20.(i) Define the term alloy and amalgam. Name the alloy used for welding electric wires
together. What are its constituents.
(ii) Name the constituents of the following alloys:
(a) Brass (b) Stainless steel (c) Bronze
State one property in each of these alloys, which is different from its main constituents.
Or
What method of concentration of ore is preferred in each of the following cases and why?
(i)The ore has higher density particles interspersed with a large bulk of low density impurities.
(ii)The ore consists of copper sulphide intermixed withclay particles.
(iii)Give an example of amalgam.
21.(i) Name the blood vessel that brings oxygenated blood to human heart.
(ii) Which chamber of human heart receives oxygenated blood?
(iii) Explain how oxygenated blood from this chamber is sent to all parts of the body.
Or
(i) Name the blood vessel that brings deoxygenated blood to human heart.
(ii) Which chamber of human heart receives deoxygenated blood?
(iii) Explain how deoxygenated blood from this chamber is sent to lungs for oxygenation.
22.(a) Name an instrument that measures electric current in a circuit. Define the unit of electric current.
(b) What do the following symbols represent in a circuit diagram:
(c) An electric circuit consisting of a 0.5 m long Nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a
plug key was set up.
(i) Draw the electric circuit diagram to study therelation between the potential difference
maintained between the points X and Y and the electric current flowing through XY.
(ii) Following graph was plotted between V and I values using above circuit:
What would be the values of VI ratios when the potential difference is 0.8 V, 1.2V and
1.6 V respectively? What conclusion do you draw from these values?

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Or
Explain the following:
(i)Why is the tungsten used almost exclusively for filament of an electric lamp?
(ii)Why are the elements of electric heating devices, such as bread-toaster and electric irons, made of an alloy rather than a
pure metal?
(iii)Why is the series arrangement of appliances not used for domestic circuits?
(iv)How does the resistance of a wire vary with its area of cross-section?
(v)Why are copper and aluminium wires usually employed
for electric energy transmission?
23.What is electromagnetic induction? Give two methodsof inducing electric current in a coil. Explain each method with the
help of diagram.
Or
Draw a labelled diagram of domestic circuit. What is the importance of earthing in a circuit?
24.State the principle on which an electromagnet works. Describe an activity to make an
electromagnet. Give two uses of electromagnet.
Or
Describe an activity to draw magnetic lines of force around a current carrying (a) straight
conductor, (b) circular loop.
Section B
25.Which of the following gas turn limewater milky:
(a) CO2 (b) SO2 (c) Both CO2 and SO2 (d) Neither CO2 nor SO2
Write chemical reactions involved.
26.A student wanted to decolourise a leaf. In which solvent, he should boil the leaf? Justify your answer.
27.The current flowing through a resistor connected inan electrical circuit and the potential difference developed across its
ends is shown in figure. Calculate the value of resistance of the resistor in ohms.

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28.Given below are the observations reported by four students I, II, III and IV for the changes observed with dilute HCl or
dilute NaOH and different materials.
The incorrectly reported observation is:
(a) I (b) II (c) III (d) IV
29.Dil. H2SO4 cannot be used in preparation of SO2 because:
(a)It is not a good oxidizing agent.
(b)It is a good reducing agent.
(c)It is bleaching agent.
(d)It is dehydrating agent.
30.A student asked to demonstrate the following two properties of sulphur dioxide gas:
I.It is heavier than air and
II.It is highly soluble in water.
Which two of the following four arrangements would the student use to demonstrate these properties:
(a) I and II (b) II and III (c) I and III (d) IIand IV
31.Medulla Oblongata is originated from:
(a) Mesoderm (b) Ectoderm (c) Endoderm (d) Ectomesoderm
32.The innermost layer of the human eye is:
(a) sciera (b) cornea (c) retina (d) lens
33.In the experiment on studying the dependence of current (I) on potential difference (V), four student set up their circuits as
shown below:

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The best set up is that of:
(a) student I (b) student II (c) student III (d)student IV
34.The following circuit diagram shows the experimental set-up for the study of dependence of current on potential
difference. Which two circuit components are connected in series:
(a) Battery and Voltmeter (b) Ammeter and Voltmeter
(c) Ammeter and Rheostat (d) Resistor and Voltmeter
35.For a current in a long straight solenoid N and S-poles are created at the two ends. Among the following statements, the
incorrect statement is:
(a)The field lines inside the solenoid are in the formof straight lines which indicate that the magnetic field is the same at all
the points inside the solenoid.
(b)The strong magnetic field produced inside the solenoid can be used to magnetize a piece of magnetic material like soft
iron, when placed inside the coil.
(c)The pattern of magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar
magnet.
(d)The N and S-poles exchange position when the direction of current through the solenoid is reversed.
36.Which is the ultimate source of energy:
(a) Water (b) Sun (c) Uranium (d) Fossil fuels

118
sample
SUMMATIVE ASSESSMENT –II
SCIENCE (Theory)
Class – X
Time allowed: 3 hours Maximum Marks: 90
General Instructions:
a)All questions are compulsory.
b)The question paper comprises of two sections, A andB. You are to attempt both the sections.
c) Questions 1 to 3 in section A are one mark questions. These are to be answered in one word or in one sentence.
d) Questions 4 to 6 in section A are two marks questions. These are to be answered in about 30 words each.
e)Questions 7 to 18 in section A are three marks questions. These are to be answered in about 50 words each.
f)Questions 19 to 24 in section A are five marks questions. These are to be answered in about 70 words each.
g)Questions 25 to 27 in section B are 2 marks questions and Questions 28 to 36 are multiple choice questions based on
practical skills. Each question of multiple choice questions is a one mark question. You are to select one most appropriate
response out of the four provided to you.
Section A
1.Complete the following reaction:
CH3 CH2 OH + Na →
2.A mirror is turned through 150
. By what angle will the reflected ray turn?
3.Name the chemicals that cause depletion of ozone layer.
4.For each of the following pairs, state which one islarger in size:
(a) Na, Na+
(b) Be, Mg (c) Br, I (d) Cl, Br
5. Name the scientific terms used to represent the following:
(a) The branch of biology which studies heredity and variation.
(b)The transmission of traits from parents to offsprings.
(c)Differences in a trait in human beings.
(d) A recognizable feature of an organism.
6.Light coming from the bottom of a water tank does not come out of the water. What should be the minimum angle of
incident for the same?
7.Electronic configuration of elements X, Y and Z is given below:
X = 2, 7 Y = 2, 8, 5 Z = 2, 8, 8
Write the position of elements in the periodic table.
8.On the basis of electronic structure, how will you select:
(a)The first element in a period.
(b)The terminating number in a period.
(c)The chemically similar elements.
9.Describe asexual reproduction in Amoeba.
10.Explain various steps of budding in yeast.
11.On the basis of possibilities of combination of thesex chromosomes, what percentage
probability does a couple have having of son or a daughter? Show the same by making a cross.
12.It is a well known fact that pregnant woman’s health is a backbone of every family and society.Using the above
information, answer the following questions:
(a)Which tissue is responsible for providing nutrition from mother to growing embryo?
(b)What according to you can be the likely measures tomaintain a woman’s health during pregnancy?
(c)What value will the learners infer from this passage?
[Value Base Question]
13.Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency
and speed of:
(a) reflected light (b) refracted light?
(μof water = 1.33)
14.A girl in the mirror laughing house finds her face appearing highly magnified, lower portion of her body of the same size
but laterally inverted and middle portion of the body highly diminished in size. Can you guess the design of the mirror?

119
15.Find the position of an object which when placed infront of a convex mirror produces a virtual image, which is half of the
size of object.
16.What is dispersion? Which colour deviates the most in a prism? Why does it take place?
17.What are the problems caused by the non-biodegradable wastes that we generate?
18.Write a note on conservation of coal and pertroleum.
19.(a) How can we use alcohol as a fuel? What are its advantages?
(b) How will you prepare soap? Explain the cleansing action of soap.
(c) Give one use of acetic acid.
Or
(a)Name two elements of group 13.
(b)Name most electronegative element in periodic table. Write its atomic number.
(c)Give limitations of Dobereiner’s law of triads.
(d)Why do ionic compounds not conduct electricity in solid state?
(e)Name the chief ore of iron. Give its formula.
20.(a) Why does carbon form largest number of compounds?
(b) Why are some of these called saturated and other unsaturated compounds?
(c) Which of these two is more reactive?
(d) Write the names of the following compounds:
(i) CH3 CH2 Br
(ii) CH3CH2CH2C≡CH
Or
Describe one method for the preparation of ethanoic acid. Give two physical properties and three uses.
21.(a) Explain with an example, how evolutionary relationship is liked to classification.
(b) A study found that children with light coloured eyes are likely to have parents with light coloured eyes. On this basis can
we say whether thelight eye colour traits to be dominant or recessive. Why or why not?
Or
(a)Why are asexually reproducing organisms capable of showing hereditary features?
(b) If the sperm bearing Y-chromosome fertilizes the egg, the child born will not be entirely like his father. Why is it so?
(c)What is the relation between heredity and variationin asexual and sexual reproduction?
22.(a) How can the pea plant be prevented from self pollination? How is cross pollination carried out?
(b) A normal pea plant bearing coloured flowers suddenly starts producing white flowers.
What could be the possible cause?
(c) Are Mendelian traits and genes similar?
Or
(a)Why is regeneration considered a method of reproduction?
(b)Is copy of DNA form identical to original cell? If yes or no, How it is beneficial to the
species?
(c)Why variation is beneficial to the species but not necessarily for the individual?
23.(a) Draw a ray diagram showing the path of a ray oflight when it enters with oblique incidence
(i) from air into water (ii) from water into air
(b) Under what condition in an arrangement of two plane mirrors, incident ray and reflected ray will always be parallel to
each other, whatevermay be the angle of incident. Show the same with the help of diagram.
Or
(a)What is refraction of light? Give an expression to relate the absolute refractive index of a medium with speed of light in
vacuum.
(b)The refractive index of water and glass with respect to air are
4/3and 3/2 respectively. If the speed of light in glass is 2 x 108
ms-1
, then find the speed of light in (i) air, (ii) water.
24.(a) A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering
from. Draw a ray diagram illustrate this effect. List its two possible causes. Draw a ray diagram to show how this defect may
be corrected using a lens of appropriate focal length.
(b) We see advertisements for eye donation on television or in newspaper. Write the
importance of such advertisements.
Or
(a)An object is placed at a distance of 15 cm from a convex mirror of focal length 20 cm. Find the position and nature of the
image.

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(b)Define refractive index. Light enters from air to diamond having refractive index 2.42. Find the speed of light in the
diamond. The speed of light in vacuum is 3 x 108
ms-1
.
Section B
25.(a) Which functional group present in acetic acid?
(b) Write its suffix (notation).
26.A student is given a permanent slide showing binary fission in Amoeba. The following are the steps in focusing the object
under the microscope:
(i)Place the slide on the stage; look through the eye piece and adjust the mirror and
diaphragm to get even illumination.
(ii)Look through the eye piece and raise the objective using coarse adjustment until the
object is focused.
(iii)Make the focus sharp wit the help of the fine adjustment.
(iv)Look through the eye piece and move the slide until the object is visible.
Now give following answers:
(a)What is the proper sequence of steps?
(b)Justify your answer.
27.(a) While performing the experiment with glass slab, what should be the range of incident angle ?
(b) Give reason for your answer.
28.Ethanoic acid was added to Sodium bicarbonate solution and the gas evolved was tested with a burning splinter. The
following four observations were reported: I.
The gas burns with the pop sound and the flame gets extinguished. II.The gas does not burn but the splinter burns with apop
sound.
III.The flame extinguishes and the gas does not burn.
IV.The gas burns with a blue flame and the splinter burns brightly.
The correct observation is reported in:
(a) I (b) II (c) III (d) IV
29.The odour of ethanoic resembles with:
(a) tomato juice (b) kerosene (c) orange juice (d)vinegar
30.During the budding, division of cell in yeast shows:
(a) Meiosis cell division (b) Mitosis cell division
(c) Both Mitosis and Meiosis cell divisions (d) No cell division occurs
31.The outgrowth of Hydra is termed as:
(a) Bulb (b) Bud (c) Daughter hydra (d) Tentacles
32.Slides A and B show stages of asexual reproduction in two different organisms. The slides A and B are depicting:
(a)Binary fission in both Amoeba and yeast
(b)Budding in both Amoeba and yeast
(c)Binary fission in yeast and budding Amoeba
(d)Binary fission in Amoeba and budding in yeast
33.A cross was made between two plants, one having variegated leaves and the other having green leaves. The F1 generation
of this hybrid produced plants all having variegated leaves. What can be the reason?
(a)Traits of variegated leave is dominant
(b)Traits of green leaves is receive
(c)Both (a) and (b)
(d)None of these
34.Your school laboratory has one large window. To find the focal length of a concave mirror using one of the walls as the
screen, the experiment may be performed.

121
(a)near the wall opposite to the window.
(b)on the same wall as the window.
(c)on the wall adjacent to the window.
(d)only on the table as per the laboratory arrangement
35.Refraction cannot cause bending as light moves fromone surface to another if the incident and refraction angles I and r are
related as:
36.The three ‘R’ rule that will help us to conserve natural resources for long-term use are:
(a) Recycle, Regenerate, Reuse (b) Reduce, Regenerate, Reuse
(c) Reduce, Reuse, Redistribute (d) Reduce, Recycle, Reuse

Class X Science Support Material

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Class X Science Support Material