Chapter3 4 notes 09
- 1. MATTER; CHAPTER 3 Elements, Compounds, Mixtures
- 2. DEMO… Place a black dot on the line drawn in pencil on your filter paper and place it in the beaker that has some water in the bottom. Make sure the dot is not under water. Watch as we take notes. What do you see?
- 3. ALL matter can be classified into 1 of 3 groups: Elements Compounds Mixtures
- 4. ELEMENTS: Simplest Pure substance Made of ONE type of atom Unique properties to identify 92 naturally occurring Organized on Periodic table with chemical symbols 3 main types…
- 6. Could you identify these elements by their density? Could you identify these elements by their conductivity? Could you identify these elements by their reactivity to oxygen? Could you identify these elements by their melting point? Cobalt Iron Nickel Melting Point: 1,495 oC 1,535 oC 1,455 oC Density: 8.9 g/cm3 7.9 g/cm3 8.9 g/cm3 Conductivity Electric and thermal energy Electric and thermal energy Electric and thermal energy Reactivity oxygen Unreactive Slowly forms rust Unreactive
- 7. So….. Can you identify elements by 1 property? Why or why not? Cobalt Iron Nickel Melting Point: 1,495 oC 1,535 oC 1,455 oC Density: 8.9 g/cm3 7.9 g/cm3 8.9 g/cm3 Conductivity Electric and thermal energy Electric and thermal energy Electric and thermal energy Reactivity oxygen Unreactive Slowly forms rust Unreactive
- 8. 1. Metals: Shiny; good conductors, malleable, ductile
- 9. 2. Nonmetals: Dull; poor conductors, brittle
- 10. 3. Metalloids: Semiconductors; Properties of both metals and nonmetals
- 11. 1. What is an element? 2. Create a word web that shows connections between the following: Elements Metals Metalloids Nonmetals 3. Describe these connections
- 13. Math and Science… The human body is made of the following elements: Oxygen; 64.6% Carbon; 18.0% Hydrogen; 10.0% Nitrogen; 3.1% Calcium; 1.9% Phosphorous; 1.1% Other; 1.3% This type of data would best be displayed using ______________ graph. Create one.
- 14. Math and Science… Percentages of Elements in the Human Body 65% 18% 10% 3% 2% 1% 1% Oxygen Carbon Hydrogen Nitrogen Calcium Phosphorous Other
- 15. HOW SMALL IS AN ATOM? (Don’t memorize these numbers!) An aluminum atom has a diameter of about ______________cm. A A piece of aluminum foil is about _________________atoms thick. 0.00000003 50,000
- 16. WHAT’S INSIDE AN ATOM? Particle Charge Location Mass Proton Neutron Electron Positive Neutral (0) Negligible 1/1836 amu Electron Clouds Nucleus 1 amu 1 amuNucleus Negative Copy this chart in your notes and use pages 87-91 to fill it in.
- 17. ATOMS AND THE PERIODIC TABLE Use the periodic table on page 158 to find sulfur and copy its square exactly in your notes. Use the key on page 158 to label each of the four pieces of information found in this square. 16 S Sulfur 32.1 Atomic Number Chemical Symbol Element Name Atomic Mass
- 18. 1. Describe the 3 “classes” that elements can be grouped into? 2. What is the smallest part of an element?
- 19. HOW ARE ELEMENTS DIFFERENT? Look at all of the different kinds of elements on the periodic table. If all protons are identical, all neutrons are identical, and all electrons are identical, how do we have such a variety of atoms? It depends on the _______________________!PROTON NUMBER
- 20. 1. What is an element? 2.What is a compound? 3.How are elements and compounds similar? Different?
- 21. THE NUMBER RULES! All elements have a model that can be drawn to show how their Protons, Neutrons, and Electrons are arranged. Look at Nitrogen shown below: 7p+ 7n 7e-
- 22. COMPOUNDS: 2 + elements chemically combined Elements react with each other Most substances on Earth Different properties than original elements
- 23. Molecules with more than 1 type of atom Chemical formulas CH4 H2O CH4
- 24. ??? What is happening to the magnesium ribbon?
- 25. EX: Magnesium + Oxygen Magnesium Oxide
- 26. BOHR MODELS… Represent compounds Ex: H2O (water) 1 P 0 N 1 P 0 N 8 P 8 N
- 27. Can be separated by chemical reactions
- 28. Flame Tests Copy the chart in your notes: Compound Flame Color Calcium chloride Potassium chloride Sodium chloride Barium chloride Lithium chloride Strontium chloride Copper chloride
- 29. Flame Tests Is this a chemical or a physical change? Why? Do you think the flame colors are caused by the chloride or the metals? Why? What color do you think sodium fluoride would have? Why?
- 30. Warm up 1. What is happening to the compounds in the soda? 2. What is a compound? 3. List 3 examples of compounds you are familiar with.
- 31. Electrolysis… Uses electric current Separates water into H and O Used to obtain aluminum, copper, peroxide
- 32. Electrolysis… Was this a chemical or physical change? How do you know? What type of matter is water (element, compound, mixture) ?
- 33. 1. How are compounds and elements alike? 2. How are compounds and elements different? 3. What are 2 ways to break down a compound?
- 34. MIXTURES: 2 + substances; NOT chemically combined NO chemical change Identities of parts DO NOT change Physically separate parts
- 35. TYPES… Homogeneous: looks like one substance Heterogeneous: different substances visible
- 37. The Liberty Bell is a mixture of: 70% copper 25% tin Small amounts of lead, zinc, arsenic, gold & silver
- 38. Demo… Look at the mixture at your desk and figure out which one you have. See if the substance is homogeneous or heterogeneous. Complete your chart. Share your data with the class.
- 39. Mixture ID Mixture Homogeneous or Heterogeneous? How To Separate? A B C D E F G H I
- 40. Mixture Names Sand and iron filings Saltwater Nuts and bolts Soft drink (gas in liquid) Saltwater and sand Air Coffee grounds and water Blood Steel (C + other elements in iron)
- 41. 1. Describe your observations of the flame tests. Was this chemical or physical change? 2.Describe your observations of the electrolysis experiment? Was this chemical or physical change?
- 42. 1. Compare and contrast compounds and mixtures. 2.What is the difference between homogeneous and heterogeneous mixtures?
- 43. SOLUTIONS: Looks like 1 substance Really 2 + substances evenly distributed Read page 76 in your textbook. Why is perfume a solution?
- 44. Demo… What do you notice about the different beakers of colored water? How would you describe them?
- 45. Solute: substance that is dissolved Solvent: substance that does the dissolving Water is the Universal Solvent
- 46. WARM UP Retrieve your paper slip with the marker streak. We completed these a few days back. 1. Discuss and list some QUALITATIVE observations about this paper. 2. What type of substance was the marker? (element, compound, mixture, etc.) 3. Use your science terms to support your answer to number 2.
- 47. EXTENSION Chromatography Can be used for many things… Forensic analysis Determine Unknown chemicals
- 48. A TASTY SOLUTION… Group Members 1 & 4: allow the candy to completely dissolve without any help Group Member 2: Allow the candy to dissolve with only your tongue moving it around Group Member 3: Allow the candy to dissolve with both tongue and teeth ***All members record time for shell to dissolve
- 49. A TASTY SOLUTION… In your solutions… 1. What was the solvent? 2. What was the solute? 3. What was the difference in dissolving rate for the different members? 4. What things can be done to change the dissolving rate of a substance?
- 50. Solubility is how much can dissolve Changes with conditions Amount of solute is called concentration
- 51. Solubility of various substances at increasing temperatures 1. What is the independent variable? The dependent? 2. Which substance is more soluble at lower temps than at higher? 3. Which substance does not change its solubility much?
- 52. Why does a can of soda get “flat” when it sits open at room temperature? When Temp Solubility of gas
- 53. Why can Mrs. Lock dissolve more ice tea mix when she boils the water first? When Temp Solubility of solids
- 54. SUSPENSIONS: A mixture; Particles are dispersed and visible but may settle out Can be separated by filtration
- 55. WARM UP 1. Why are suspensions considered mixtures? 2. Why is a snow globe a good example of a suspension?
- 56. WARM UP 1. What are the properties of a solution? 2. What are the properties of a suspension?
- 57. COLLOIDS: Properties of solutions and suspensions Small particles Mixed well; don’t settle out; scatter light Can’t be separated by filtration Types of mixtures…
- 58. Demo… Is this a colloid? Why?
- 59. Why is this a colloid?
- 60. Why is this a colloid?
- 61. Type Homogeneous or Heterogeneous 1. Oil and water 2. Chicken broth 3. Milk 4. Granite (rock) 5. Soda (gas in liquid) 6. Salt water 7. Raisin bran 8. Toothpaste 9. Sand and water 10. Oil and vinegar 11. Mayonnaise 12. Kibble and Bits Solution, Colloid, Suspension
- 62. WARM UP… 1. Take out your textbook and uncover it 2. Clean any papers out of the book-recycle them! 3. Get out a PENCIL for the test