In NO3- ion number of bond pair and lone pair of electrons on nitrogen atom are?
Each atom in these structures is surrounded by four pairs of electrons, the first cardinal rule in writing a Lewis structure. On the average, one electron of the pair in each bond belongs to one atom. Since there are only four bonds to N and no unshared valence pairs, N on the average has but four valence electrons in these three structures. The N atom initially possessed five electrons, and a plus sign is placed at N to denote that it has, on the average, one less electron in the NO3- ion. The two singly-bonded oxygens have on the average seven electrons in each structure, one more than a neutral oxygen atom. This is denoted by a minus sign. The doubly-bonded O has on the average six electrons. Notice that the sum of these formal charges is minus one, the correct charge for the NO3- ion.
Therefore, nitrogen has 4 bond pairs and 0 lone pairs.