Question

Does `NO_3` obey the octet rule?

Answer 1

Certainly `NO_3^-`, `"nitrate anion"`, does.

Explanation:

For nitrate ion there are `1+5+3xx6=24" valence electrons"` to distribute. The Lewis structures show charge separation, and localized charges on nitrogen on oxygen.

`O=N^(+)(-O)_2^-`

Around the nitrogen and each oxygen atom there are 8 electrons. The formal charge is as given. Of course, the oxygen atoms in the structure are equivalent by resonance.