# What is a polyatomic ion? What is an example?

$N {O}_{3}^{-}$, $S {O}_{4}^{2 -}$, $H P {O}_{4}^{2 -}$, $C {r}_{2} {O}_{7}^{2 -} \ldots .$
...${O}_{2}^{2 -}$, $C l {O}_{4}^{-}$, $C l {O}_{3}^{-}$, $M n {O}_{4}^{-}$, ${I}_{3}^{-}$....all of these species are polyatomic ions that can form salts with counterions.....