In a physical change, no new substance is formed. Hence, the tearing of paper is a physical change.
Properties such as shape, size, colour and state of a substance are called its physical properties. A change in which a substance changes its physical properties is called a physical change. A physical change is generally reversible. In such a change, no new substance is formed.
Examples of Physical Changes
- Crushing a can.
- Melting an ice cube.
- Boiling water.
- Mixing sand and water.
Cut a piece of paper into four square pieces. Cut each square piece further into four square pieces. Lay these pieces on the floor or a table so that the pieces acquire the shape of the original piece of paper. Here is the property of the paper changed.
A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction. All new substances are formed as a result of chemical changes. For example, digestion of food in our body, ripening of fruits, fermentation of grapes, etc., happen due to a series of chemical changes.
Examples in everyday life are:
- Burning of paper and log of wood.
- Digestion of food.
- Boiling an egg.