Question

What is the difference between a pigment and a compound? Why is chlorophyll called a pigment?

Answer 1

The natural coloring matter of plants and animals is called a pigment. They selectively absorb or reflect certain wavelengths and hence change the color of reflected light.

Compounds are made up of one or two elements chemically combined to give a molecule.

Pigments are compounds with special properties of selective absorption and reflection of light. Chlorophyll absorbs all light except green, it reflects green and thus anything containing chlorophyll appears green. Hence it is a pigment.