1. Focus 4 October 24, What is the difference between a chemical change and a physical change? 2. What are the 6 signs of a chemical change?

2. What is a Physical Change?
A physical change alters the form of a substance, but does not change it to another substance.
The change could be undone—if you know how
Example:
Making Orange Juice

3. What is a Chemical Change?
When a substance undergoes a chemical change, it is changed into a different substance with different properties.
Example:
Baking a Cake

4. Property – trait or characteristic.
Every substance has its own special properties
Chemical state (solid, liquid, gas)
Boiling point, freezing point
Color, density

5. 6 Signs of a Chemical Change
Color Change
Precipitation

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

7. 6 Signs of a Chemical Change
Gas Production
Temperature Change

8. 6 Signs of a Chemical Change
Makes light
Odor production

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