Molecule

Molecule

A molecule is the smallest particle of an element or compound that can exist independently. E.g. molecule of water (compound), sodium chloride (compound), molecule of oxygen(element), etc.

There are many elements which have only one atom in one molecule, e.g. copper, silver, lead, mercury etc.

Although most elements can exist independently but atom of some elements cannot exist independently and their molecules have two atoms. These elements are – oxygen, hydrogen, nitrogen, chlorine, iodine, bromine and fluorine.