Which of the following orders of resonance energy is correct?

The difference in energy between the actual structure and the lowest energy resonance structure for the given compound is

The resonance hybrid of the nitrate ion $(NO_3^-)$ is represented by:

$A$ molecule may be represented by three structures having energies $E_1$,$E_2$ and $E_3$,respectively. The energies of these structures follow the order $E_3 < E_2 < E_1$. If the experimental bond energy of the molecule is $E_0$,the resonance energy is

What is the $O-O$ bond length in the ozone $(O_3)$ molecule (in $pm$)?

Which one of the following is not a resonance structure of $CO_2$?