Question

Give an example of a physical change.

Answer 1

Hint: A physical is a Reversible process in which no new substance is formed. In this type of reaction there is no change in molecular composition of the substance. And a small amount of energy or no energy is absorbed or released in the process. So, based on the above definition we can identify a chemical change.

Complete answer:
There are generally two types of reactions based on their reversibility, one is physical change and the other one is chemical change.
So, if we consider physical change, it is a reversible process in which no new substance is formed and the molecular composition remains unchanged. In this type of reaction, a small amount of energy or no energy is released or absorbed.
Therefore, we can say that physical change is a temporary process in which the product can get back to its initial state.
For example: If we put water (liquid state) into the freezer, it will get converted into ice (solid state), but when the ice is put at room temperature, it again becomes liquid water and comes back to its initial state. Hence freezing of water into ice is considered as a physical change.

Note:
One other change is chemical change, which is an irreversible process in which a new substance is formed. In this type of reaction there is a change in molecular composition observed. It always includes absorption or release of energy and it is considered as a permanent change.