What do you mean by pure substance?

• Matter can be broken down into two categories: pure substances and mixtures. 

• Pure substances are further broken down into elements and compounds

• An element is a pure substance, which is made up of only one kind of atoms. It cannot be further reduced to simpler substances by any physical or chemical methods. An atom is the smallest unit of an element.

• A compound is a pure substance that consists of two or more elements combined chemically in a fixed proportion by weight. It can be broken down into elements by chemical methods only.