Chapter 8, Problem 103QP

Hydrazine, ${\text{N}}_{\text{2}}{\text{H}}_{\text{4}}\text{,}$ is a colorless, oily liquid that fumes in air and has an odor much like that of ammonia. It is used as a rocket fuel. The order of its atoms is ${\text{H}}_{\text{2}}{\text{NNH}}_{\text{2}}\text{.}$ How many unshared pairs of electrons are on each nitrogen atom?