Question

What is the resonance structure of carbon dioxide?

Answer 1

Carbon dioxide, or `"CO"_2`, has three resonance structures, out of which one is a major contributor.

The `"CO"_2` molecule has a total of 16 valence electrons - 4 from carbon and 6 from each oxygen atom.

Here are the three resonance structures for `"CO"_2`, all accounting for the 16 valence electrons

The atoms in all three resonance structures have full octets; however, structure 1 will be more stable, and thus contribute more, because it has no separation of charge.

Structures 2 and 3 show charge separation caused by the presence of formal charges on both oxygen atoms. Moreover, the presence of a positive charge on oxygen further reduces the stability of these two structures.