Which of the following statements are true for the nitrate ion $(NO_3^-)$?
$(a)$ The coordination number of $N$ is $3$,and the structure is trigonal planar.
$(b)$ The formal charge on $N$ is $+1$.
$(c)$ The average formal charge on each $O$ atom is $-2/3$.
$(d)$ The average bond order of the $NO$ bond is $4/3$.
$(e)$ All $NO$ bond lengths are identical due to resonance.
Select the correct code:

Identify the species having one $\pi$-bond and the maximum number of canonical forms from the following:

What points should be kept in mind while writing resonance structures?

Given below are two statements :
Statement $I$ : Experimentally determined oxygen-oxygen bond lengths in the $O_3$ are found to be same and the bond length is greater than that of a $O=O$ (double bond) but less than that of a single $(O-O)$ bond.
Statement $II$ : The strong lone pair-lone pair repulsion between oxygen atoms is solely responsible for the fact that the bond length in ozone is smaller than that of a double bond $(O=O)$ but more than that of a single bond $(O-O)$.
In the light of the above statements,choose the correct answer from the options given below:

Give rules for writing resonance structures.

Which of the following pairs of structures does not represent resonating structures?