1. Physical and Chemical Changes

2. What is a Physical Change?
A change in a substance that does not involve a change in the identity of the substance
Example:
Crumpling paper

3. Examples of a Physical Change
Grinding
Cutting
Melting
Boiling

4. What is a Chemical Change?
A change in which one or more substances are converted into substances
Example:
Baking a Cake

5. Signs of a Chemical Change
Color Change

6. Signs of a Chemical Change
Precipitation – the solid that forms from a solution during a chemical reaction.
It looks like a cloudy solid in an otherwise clear solution.

7. Signs of a Chemical Change
Gas Production

8. Signs of a Chemical Change
Changes in Characteristic Properties
(odor, light given off)

9. Chemical or Physical Change?
Cutting paper?
Physical

10. Chemical or Physical Change?
Ice melting?
Physical

11. Chemical or Physical Change?
Toast burning?
Chemical

12. Chemical or Physical Change?
Rocket fuel burning?
Chemical

13. Chemical or Physical Change?
Sawing wood?
Physical

14. Chemical or Physical Change?
Metal rusting?
Chemical

15. Chemical or Physical Change?
Disappearing puddle?
Physical

16. Chemical or Physical Change?
Candle burning?
Chemical

17. Chemical or Physical Change?
Dry ice?
Physical