# What is the difference between an ionic compound and a polyatomic ion?

Well, an ionic compound, e.g. $N a C l$, $C a B {r}_{2}$, is a NEUTRAL salt composed of ions.....
And a polyatomic ion is an anion or cation, that bears an excess or deficiency of electrons, e.g. $N {H}_{4}^{+}$, or $N {O}_{3}^{-}$.....