# Why is a polyatomic ion not called a molecule?

Apr 21, 2014

Polyatomic ions contain two or more atoms bonded together in a manner that there is still a charge on the molecule.

Monatomic ions are charged atoms of single element,

Examples of monatomic ions include, sodium ions are $N {a}^{+}$ and Fluoride ions are ${F}^{-}$,

However, examples of polyatomic ions are $N {O}_{3}^{-}$, $P {O}_{4}^{- 3}$ and $N {H}_{4}^{+}$. In each case the ion is composed of more than one atom.