Physical And Chemical Changes

Question 1

Examples of physical changes:

Answer 1

Tearing a piece of tin foil.

Crumpling a piece of paper.

Question 2

Examples of chemical changes:

Answer 2

Burning wood

Rotting an apple

Question 3

Differences between the two:

Answer 3

1. A physical change is reversible, a chemical change is not. For example, the freezing of water would be a physical change because it can be reversed, whereas the burning of wood is a chemical change – you can’t ‘unburn’ it
2. A physical change is a change in which no new substance is formed; a chemical change results in the formation of one or more new substances. Again, consider the previous examples: Freezing water into ice just results in water molecules which are ‘stuck’ together – it’s still H2O. Whereas burning wood results in ash, carbon dioxide, etc, all new substances which weren’t there when you started.

You’re messing around with the physical structure object, but that’s it.