What is Formulae in Chemistry?

Definition: The formulae of a molecule gives the numbers of atoms of the same or different elements present in the molecule.

Formulae of elements:

1. When an atom of an element combines with another atom(s) of the same element, a molecule of the element is formed.
2. For example, two atoms of hydrogen combine to form a molecule of hydrogen. So the formulae of hydrogen are H2.
3. Molecules of nitrogen, oxygen, fluorine, chlorine, bromine and iodine.contain two atoms of the element. As these molecules have two atoms of the element, they are called diatomic.
4. The molecules are having three atoms of an element called triatomic. For example, ozone(O3) is a triatomic gas.
5. The molecules having one atom of an element is called monoatomic. A molecule of noble gas contains only one atom of an element. For Example helium, neon, argon, krypton and xenon.
6. The formulae of the noble gas are the same as its symbol.