# Are all polyatomic ions ionic?

• ${\text{CrO}}_{4}^{2 -}$ is ionic within itself and with respect to its interactions with OTHER substances. It contains a metal interacting with four nonmetals, and is clearly charged.
• ${\text{CO}}_{3}^{2 -}$ is molecular within itself and ionic with respect to its interactions with OTHER substances. It contains carbon and three nonmetals, but is clearly charged.