Which of the molecules and polyatomic ions cannot be adequately described using a single Lewis structure

The question is incomplete, the complete question is;

Which of the molecules and polyatomic ions cannot be adequately described using a single Lewis structure?

O3

OF2

CH2Cl2

NH4+

HCN

CO3^2-

O3, CO3^2-

Explanation:

The molecule, ozone (O3) and the carbonate ion ( CO3^2-) are both represented using canonical structures. A single Lewis structure does not sufficiently account for all the observed properties of these substances.

Since one lewis structure is insufficient in explaining their properties, this molecule and polyatomic ion can only be described by a hybrid structure known as a resonance hybrid.