1. Physical and Chemical Changes

2. Matter Can be described as
Physical property – description of substance. Ie. Colour, smell, taste, density.
Chemical property – Describes how a substance reacts when mixed with other substances. ie. Gas burns in heat and oxygen.

3. Physical Change A change that does not produce a new substance.
Usually reversible
e.g. melting ice, dissolving salt

4. Chemical Change A reaction takes place creating a new substance.
Usually hard or impossible to reverse.
Ex. Cooking an egg

5. There are 5 clues that a chemical change may have occurred…
1. A new colour appears.

6. 2. Heat or Light is given off.

7. 3. Bubbles of Gas are formed.

8. 4. A new solid material forms (precipitate).

9. 5. A new odour is made.

10. What do you think? 1. Sugar dissolving in tea?
2. Breaking water up into hydrogen and oxygen gas?
3. Burning a log in a campfire?
4. Crushing an Aspirin?
5. Metal Rusting?
6. Lighter fluid burning?
7. An egg rotting?
8. Boiling water?
9. Test tubes in picture  ?