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

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

What are some physical properties of mercury ?

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

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

Chemical Property Combustibility (flammability)

Physical vs. Chemical Changes

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

Examples : Cutting wood Is it still wood?

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

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

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

Example : Burning items

Example : baking cake

Example: Rust

rust

tarnish

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