# How do you find the bond order of NO_3^-?

The bond order is the average, $\text{4 electron pairs" / "3 bonds}$ $=$ $\text{4/3 electron pairs per bond}$.
The Lewis structure of nitrate ion is unusual because it features 3 formal charges in that the nitrogen is quaternized and formally cationic, and 2 of the oxygen atoms have formal negative charges. Of course, the sum of the charges $+ 1 + 2 \times \left(- 1\right) = - 1$ for a uninegative ion.