1. Chemical Changes

2. Physical Change Ice melting Sharpened pencil
Matter changes in size , shape , or state with out changing identity . Can be reversed
Example:
Ice melting
Sharpened pencil

3. 3 examples of physical changes are...
piece of paper is cut up into small pieces
This would be a physical change in the shape and size of the paper .

4. Mix salt into water to create saltwater.
this would be a physical change as the water could be left out to evaporate and the salt crystals would remain

5. Changing ice into water
For example, a cup of water can be frozen when cooled and then can be returned to a liquid form when heated

6. Chemical Change burnt toast Rusty nail Tarnished silver
Chemical changes occur when atoms link together to cause new compounds to form a new substance
burnt toast
Rusty nail
Tarnished silver

7. What are the 3 signs of chemical changes?
Color change
Formation of light and heat
Formation of gas

8. Reactamts An original substance at the beginning of a chemical change
Example : ingredients to bake a cookies

9. Products A new substance produced by a chemical change Example:
Cookies are produced
After you mix all the
ingredients and bake it

10. Example of a chemical change
Baking a cake
Reactants
flour, water, sugar and other ingredients mixed together
The cake
Product

11. Why are chemical
changes
harder to
reverse than physical?
In a chemical change a new substance is formed and physical change only changes in appearance