Give examples to explain the difference between changes that can or cannot be reversed.

Change in shape/nature of an object can be of two types. They are reversible changes and irreversible changes.

a) The changes in which the object/matter can be brought back to its original state is known as reversible changes.

Example: Melting of ice

Ice melts when it gets hot and turns into water, which can then be transformed back into ice by lowering the temperature (by keeping it in the freezer). This is a reversible process.

b) The changes in which the object/matter cannot be brought back to its original state is called irreversible changes.

Example: Burning of a piece of paper

A piece of paper is converted into ash when it is burned. It is an irreversible change because these ashes cannot be changed back into paper.