What is a (a) physical change, and (b) chemical change ? Give two examples of physical changes and two examples of chemical changes.

Explanation

Physical Change: Properties like size, shape, state (solid, liquid or gas), temperature, pressure etc., are physical properties. Those changes in which only physical properties of a substance changes are called physical changes. For example, lightening of bulb is a physical change and folding of paper is a physical change.


Chemical Change: The change in which new substance is formed and chemical composition of a substance is changed is called a chemical change. A substance loses its identity in a chemical change and cannot be get back into its original form. For example, burning of candle, formation of curd etc.