I have a structure set up that is H2C=N=N with two pairs of electrons.
Perhaps I'll describe H
2C=N=N in terms of the number of electrons on each atom in the molecule.
Each H contain only a bonding pair (C-H) each.
The C atom contains 4 bonding pairs.
The N attach to C has 4 valence electron. It has donated its 5th electron to the other N atom and inherit a positive charge on it. It exhibits a valency of 4, thus contains 4 bonding pairs.
The last N has 6 valence electrons. It accepted it 6th electron from the othe N atom, thus inherit a negative charge. It exhibits a valency of 2, thus forming double bond with the N atom.