What is the oxidation state of nitrogen in N2?
O A. +5
O B.-3
O C. +3
O D. O

D) 0 (zero)

Explanation:

There's a rule that neutral compounds (compound) without charges have oxidation of zero. Also, another formula that if two atoms of the same element make one single molecules such as diatomics molecules are O2, N2, I2, Br2 oxidation states are zero, thus here N is 0 (Zero) as well.

it means there are 3 atoms of oxygen