Our world is made up of many different kinds of substances that we call chemicals. All matter, including us and everything around us, is made up of tiny particles called atoms. So, what is a chemical? A chemical by definition is any substance consisting of matter; this includes solids, liquids, and gas. Chemicals can either be of a pure substance or a mixture of substances.

A chemical substance such as water (H2O) is a pure chemical because it has the same molecules and combination throughout its structure. (Source: Reagent)