Oxidation number of N in N3H (hydrazoic acid)

Answer: 

N in N3H has oxidation number -1/3.

Oxidation number can be defined as the total number of electrons that atoms in a molecule can lose, share or acquire while building a chemical interaction with atoms of other elements. 

Solution-

Here in N3H, we have 3 nitrogen atoms and 1 hydrogen atom

So, let us assume,

The oxidation number of N in N3H is x,

3x + 1 =0

or 3x = −1

3x= −1

Therefore,

x = −1/3