Question

what is the correct lewis diagram for the carbonate ion?

Explanation:

Lewis diagrams for polyatomic ions must show the ion's charge in brackets. Carbonate (\(CO_3^{2 - }\)) has a double bond to one oxygen (to satisfy carbon's four - bond requirement and octet rule for all atoms). The first option lacks a double bond (carbon would have only three bonds). The third option misses the brackets for the charge. The fourth option is missing the double bond.

Answer:

The second option (the one with a double bond to one oxygen and the \(2-\) charge in brackets) is correct.