# What is the reduction half-reaction for the following overall cell reaction?

$N {i}^{2 +}$ + $2 {e}^{-}$ $\to$ $N i$
Reduction is a gain of electrons. In the reaction stated above there is an increase in number of electrons from $+ 2$ $\to$ $0$ by gaining two electrons . Note that increase in number of electrons= decrease in oxidation number.