Question

What are physical and chemical changes? Give two examples of each.

Answer 1

Physical change:

1. A change in which the physical properties of a substance change but no new substance is formed is known as a physical change.
2. It is a temporary change and can be reversed easily by changing the conditions.
3. Example - glowing of a bulb, boiling of water.

Chemical change:

1. A chemical change is a change in which a new substance is formed.
2. It is a permanent change and cannot be reversed easily.
3. Example - burning of the candle to give carbon dioxide and water, electrolysis of water.