Question

A change, which alters the composition of a substance, is known as a ___________ change.

Answer 1

Chemical change:

• A chemical change is a permanent change in which new substances are formed.
• The chemical change is permanent and cannot be reversed by a simple physical method.
• A chemical change involves an exchange of energy in the form of heat or light.
• During this change, one or more new substances with composition and properties different from the original substances are formed.
• For example, rusting of iron, burning of wood, respiration, etc.

Therefore, a change, which alters the composition of a substance, is known as a chemical change.