The carbonate ion CO3^2- has three possible resonance structures. Resonance occurs in this molecule because the electrons in the double bond can be delocalized among the three oxygen atoms, resulting in a more stable structure. Here are the three resonance structures:1. O=C-O^- -O^- 2. O^- -C=O-O^- 3. O^- -O-C=OIn each structure, the carbon atom forms a double bond with one of the oxygen atoms and single bonds with the other two oxygen atoms. The two oxygen atoms with single bonds each carry a negative charge, while the oxygen atom with the double bond has no charge. These structures are equivalent, and the actual structure of the carbonate ion is a hybrid of these three resonance forms.The resonance in the carbonate ion allows the negative charge to be distributed evenly among the three oxygen atoms, which increases the stability of the ion. This delocalization of electrons also results in the carbonate ion having a lower energy state than any single structure, making it more stable overall.