Total number of non bonded electrons present in $$NO_{2}$$ -ion based on Lewis theory is

The Lewis structure of $$NO_2^-$$ (nitrite ion):

Nitrogen has 5 valence electrons, each oxygen has 6, plus 1 for the negative charge: Total = 5 + 2(6) + 1 = 18 electrons.

Structure: $$[:O-N=O:]^-$$ with a lone pair on N.

Non-bonded electrons (lone pairs):

- Nitrogen: 1 lone pair = 2 electrons

- Oxygen (single bond): 3 lone pairs = 6 electrons

- Oxygen (double bond): 2 lone pairs = 4 electrons

Total non-bonded electrons = 2 + 6 + 4 = 12

The answer is 12.