Study Guide Unit Test (9-18-14)

Study Guide – Unit Test (9-18-14) 1. What is a physical property? 2. What is a physical change? 3. What is a chemical property? 4. What is a chemical change?

5. You need to know the definition and examples of the following physical/chemical properties: Volume – amount of space an object takes up (plant growing) Mass – amount of matter in an object (cutting an object in two pieces) Ductility – ability to be pulled into wires (copper) Malleability – ability to mold, bend, and press into sheets (aluminum foil) Solubility – ability to dissolve (salt water) Viscosity – liquid’s resistance to flow (syrup has a high viscosity compared to water) Buoyancy – ability to float (boat, cork) Freezing Point – temperature at which a liquid turns into a solid (water freezes at 0 degrees Celsius) Melting Point – temperature at which a solid turns into a liquid (Popsicle in the sun) Boiling Point – temperature at which a liquid turns to a gas (water boils at 100 degrees Fahrenheit) Flammability – ability to burn (paper or wood burning) Combustibility – ability to explode (gun powder exploding) Reactivity (with water, acid, and oxygen) – ability to cause a chemical change when in contact with another substance (Statue of Liberty)

6. You need to be able to distinguish between a physical and chemical change: Glass Breaking (Physical) Rusting (Chemical) Cooking of any kind (Physical) Ice Melting (physical) Salt/Sugar Dissolving (Physical) Wood Burning (Chemical) Crushing a can (physical) Water Evaporation/condensing (physical) Dry Ice Subliming (physical) There will be other examples included on the test. (Look at notes/old quizzes and worksheets)

7. Signs that a chemical change has occurred: Foaming/Fizzing Change in color Change in odor Rapid production of heat, light and/or sound Production of a new substance with different properties

8. Law of Conservation of Mass – matter is never created or destroyed in a chemical reaction.

Example: If a sealed container with 10 grams of baking soda and 6 grams of vinegar is combined, the amount of liquid will decrease because the chemical reaction between the two substances creates CO2 (Carbon Dioxide gas), however the mass inside the container is still 16 grams. You cannot see the gas, but the matter was not destroyed.