1. Physical Properties – Can be observed or measured without changing the identity of the substance

2. Physical Properties Examples: 1. color 2. odor 3. phase 4. Density 5. heat or electric conductor 6. Hardness 7. Boiling and Melting points 8. Streak test

3. What are some physical properties of mercury ?

4. Chemical Properties - Describe a substance’s ability to react chemically with other substances.

5. Chemical Properties examples: Reactivity – ex. sodium metal reacts with water

6. Chemical Property Combustibility (flammability)

7. Physical vs. Chemical Changes

8. Physical Change - A change in the physical properties, but does not change the identity of the substance

9. Examples : Cutting wood Is it still wood?

10. Example: Change in state All three are still H 2 O

11. Chemical change - When two or more substances (reactants), combine to form a new substance (the product)

12. Signs that a chemical change occurred. new product is formed heat or smoke produced Bubbles produced

13. Example : Burning items

14. Example : baking cake

15. Example: Rust

16. rust

17. tarnish

18. Law of conservation of Mass Matter (mass) cannot be created nor destroyed during a chemical change. Mass of Reactants = Mass of Products Water + alka seltzer = water +sodium citrate + carbon dioxide