1. Chemical and Physical Changes

2. Physical Changes
A change in the size, shape, state, or form of matter. No new substance is made. Ex
Crumpling paper
Dissolving
Ice melting
Cutting something in half
Blowing up a balloon

3. Chemical Changes
A change in matter where one or more substances change into new substances with different chemical and physical properties.
Ex:
Fire
After a log is set on fire, it is not a log anymore, it is ash and gas.

4. How to Spot a Chemical Change
A NEW gas is made
When a new gas is formed, it is a new substance that has been made. If a substance changes into its gas form, that is a physical change.
A precipitate forms
When two or more substances are combined and a new solid forms.
Color change
Color changes indicate chemical change.

5. Energy and Chemical Change
Chemical changes require energy changes.
Energy is taken in
Baking food
Baking soda and vinegar
Energy is released
Fireworks
bombs

6. Reversing a Change Most chemical changes cannot be reversed
Fireworks cannot change back
You can’t remake an Alka-Seltzer tablet
Some physical changes can be reversed
You can flatten out a piece of paper
You cannot un-grate a carrot
You can separate salt from water it was dissolved in.