Question

Differentiate between physical and chemical change with an example?

Answer 1

There are two possible definitions for Physical and Chemical changes which I use in school: 

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.

Answer 2

Answer:

Physical changes :-

1 A change in which a substance

undergoes change in its

physical properties are called

physical changes.

2. These changes are temporary

and can be reversed.

3. No new substance is formed in

physical changes.

Examples

1. Melting of ice

2. Freezing of water

3. Cutting of paper

Chemical changes:-

1.A change in which a substance

undergoes change in its chemical

properties are called chemical

changes.

2.These changes are permanent and

hence are irreversible.

3.New substance is formed in

chemical changes.

Examples:-

1. Burning of magnesium

ribbon

2. Rusting of iron

3. Burning of paper