Maharishi Kannad in 300 B.C opined that if you divide matter you will find a Paramanu. Paramanu means a stage that you cannot divide further. Indian philosopher, Padukha Katayayama in 500 B.C proposed “Paramanus” combine and exist in the form of molecules. Atom in Greek means indivisible and is the smallest unit of matter. All matter whether is it is a solid, liquid, gas or plasma all are made up of atoms. Molecules on the other hand is made of atoms held together by chemical bond and is electrically neutral. Ions on the other hand are the charged particles.