# How many electrons in the nitrite ion, NO_2^(-)?

Apr 30, 2016

$\left(O =\right) N - {O}^{-}$

#### Explanation:

No. of valence electrons: $= 2 \times 6 + 5 + 1 = 18$.

So around each atom (from left to right above), there are 6, and 5, and 7 valence electrons. Because there are 7 valence electrons around the rightmost oxygen (i.e. 9 electrons in total including the inner shell electrons), this oxygen has a formal negative charge.

Of course there is a resonance isomer: ""^(-)O-N(=O).

The neutral nitrogen atom has a formal lone pair in each mesomer.

How would you describe the structure of this ion based on VSEPR?