Physical and Chemical Changes

Matter Anything that has mass and takes up space (has volume). Matter Pure Substances Elements e.g. carbon Compounds e.g. CO2, H2O Mixtures Solutions e.g. salt water Mechanical e.g. pizza

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.

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

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

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

2. Heat or Light is given off.

3. Bubbles of Gas are formed.

4. A new solid material forms (precipitate).

5. A new odour is made.

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  ?