What is the resonance structure of carbon dioxide?
Carbon dioxide, or
Here are the three resonance structures for
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.