An oxyanion is a polyatomic ion that contains oxygen and has a net negative charge. examples are \rm {so_4}^{2-}, \rm {no_3}^{-}, and \rm {co_3}^{2-}. in many oxyanions, the oxygen atoms form one single bond with three lone pairs, giving them each a formal charge of -1. \displaystyle \normalsize : \underset {{}^{\huge{..}}} {\overset {\large{..}}{\rm o}}\! - however, if this bonding arrangement does not give the central atom an octet of electrons, multiple bonds form between the central atom and one or more of the outer oxygen atoms. an oxyanion may combine with a cation to form an ionic compound. examples are \rm k_2so_4, \rm nano_3, and \rm caco_3. part a draw the structure of \rm {no_3}^{-}. draw the ion by placing atoms on the grid and connecting them with bonds. include all lone pairs of electrons. use square brackets to denote the overall charge. view available hint(s)