Elements, Compounds & Mixtures Slides
- 1. Elements, Compounds & Mixtures
- 2. Matter Elements Compounds Mixtures
- 3. Elements A pure substance that cannot be decomposed into two or more simpler substances by chemical processes or electricity
- 4. Elements Elements are represented by chemical symbols . These symbols are found in the Periodic Table . contains ALL known elements
- 5. Elements Match the symbols to their elements. Cl Arsenic Na Sulfur Mg Chlorine As Magnesium S Sodium
- 6. Metals Non-Metals Dull (solids) Gases, volatile liquids or solids at r.t.p** Brittle (solids) Low Melting & Boiling Points** Poor conductors of heat** Poor conductors of electricity** Shiny Solids at r.t.p** - Malleable - Sonorous - Ductile High Melting & Boiling Points** Good conductors of heat Good conductors of electricity
- 7. Elements Made up of particles known as atoms
- 8. Elements Atoms are the smallest particles of an element chemical properties of that element
- 9. Elements Monoatomic Molecules Single atoms Example: Group 0 elements Metals >1 atoms joined chemically together Example: Most non-metals like ozone, hydrogen O 3 : triatomic H 2 : diatomic Kr
- 10. Elements Give three reasons why Cu is used to make electrical wires. Give an example of a diatomic element and its symbol.
- 11. Molecules Elements Compounds Same type of atom (one element) Example: Different types of atoms (>1 elements) Example: O 3 : triatomic H 2 : diatomic O H H H 2 O triatomic
- 12. Quiz Which of the following are representations of compounds? O H H O C C N N
- 13. Compounds
- 14. Compounds A pure substance that Contains 2 or more elements Chemically combined S eparated by chemical means
- 15. Compounds P roperties are different from its parent elements
- 16. Compounds Since compounds are chemically combined, their formation involves an E nergy change
- 17. Compounds C omposed of different elements combined in a fixed ratio Hydrogen + Oxygen Water 2 Hydrogen + 1 Oxygen 1 Water
- 18. Naming Compounds Compounds made up of 2 elements: –ide Zinc ox ide , sodium chlor ide Hydroxide ions, OH - : hydroxide Sodium hydroxide Polyatomic ions containing oxygen: -ate Copper(II) sulf ate , sodium nitr ate , sodium carbon ate
- 19. Compounds Guess the elements present Sulfur dioxide Silver nitrate Iron(II) sulfate Nitrogen dioxide Magnesium chloride
- 20. Compounds Elements are represented by symbols Compounds are represented by chemical formula
- 21. Chemical Formula of Compounds Chemical formula informs us of the Elements present Ratio of elements
- 22. Chemical Formula of Compounds Rules: 4) Carbon Dioxide, C O 2 4) Oxygen is usually written at the end (except for hydroxide) 3) Water, H 2 O not H 2 O 1 3) Need not write subscript ‘1’ 2) Magnesium Carbonate, MgCO 3 2) Number of atoms is written on the right of the symbol 1) Calcium Oxide, Ca O 1) Metallic element is written first
- 23. Compounds Compounds can decompose into simpler substances when heat is applied Thermal Decomposition
- 24. Mixtures Two or more substances Added together Without chemical bonds being formed Impure Substances
- 25. Mixtures Can be made up of; Elements + Elements Alloys Elements + Compounds Air Compounds + Compounds Our Body
- 26. Mixtures S eparated by physical means Chromatography Filtration Distillation Crystallization
- 27. Mixtures P roperties are same as its parent elements or compounds
- 28. Mixtures Since no chemical bonds are formed, formation of mixtures involves No E nergy change
- 29. Mixtures C omposed of different substances combined in a variable composition Composition of air: 20% O 2 , 79% N 2, 1% other gases Not Fixed!
- 30. Alloys Mixture of metals with other elements Stronger than pure metals Eg: steel (Fe + C) brass (Cu + Zn) solder (Pb + Sn)