1. Changes in Matter Physical Change Can be reversed
No new material created
Phase change

2. Chemical Change
Cannot be reversed
New substance made
One or more of the following occur:
* color change
* temperature change (hotter or colder)
* flashes of light or sound
* gas produced ~ bubbles
* new odor

3. Signs of Chemical Reactions
There are five main signs that indicate a chemical reaction has taken place:
release
input
change in color
change in odor
production of new
gases or vapor
input or release
of energy
difficult to reverse

4. Physical or Chemical Change

5. Frying an Egg

6. Chemical
Color change
Odor change
Cant turn it back into raw egg

7. Boiling Water

8. Physical Change in state of matter only
Can turn steam back into liquid
Molecules are still H2O

9. Burning gasoline

10. Chemical
New material made
Odor change
Cant turn back to gasoline

11. Sour Milk

12. Chemical Odor change Taste change New chunky substance made
Cant turn back to milk

13. Compression of a spring

14. Physical
Still a spring
Returns to normal shape after it is released

15. Rusting bicycle
timberspringsphotography.com

16. Chemical Color change Texture change Cant turn back to metal
New material

17. Gases No definite shape Lots of energy Volume can change
Often created in a chemical reaction

18. Oxygen O
Colorless
Odorless
Tasteless
Flammable
Fuels a fire

19. Hydrogen H Colorless Odorless Tasteless Explosive in fire
Makes a “popping” noise
In fire

20. Carbon Dioxide CO2
Colorless
Odorless
Tasteless
Dense
Puts out a fire

21. Test for Type of Gas
Glowing wood splint