Question

give reasons - light is energy

Answer 1

light is energy because light helps the plant to photosynthesize and make food for themselves, as the plant grows human intake them as food which provides them with energy to live. so, we can say that the root source of energy is light, if there wont be light there won't be life.

Answer 2

Light which we see is a electromagnetic radiation, any electric charge which accelerates or any changing magnetic field produces electromagnetic radiation. The photon is the quantum of electromagnetic interaction and basic unit of light and all forms of electromagnetic radiation and also the force carrier for electromagnetic force.
We also know that energy is the ability to do work, also one form of energy can be converted to other. So light photon can cause electricity which the form of energy. The photon posses some energy which used in a electron of an conductor.
Example - When you go out in the hot blazing sun we can fell our body getting warmed which shows that light posses energy.(Heat is a form of energy.)