Cobalt (II) cation has a +2 charge. Hydroxide anion has a -1 charge.
Work Step by Step
There is no overall charge on the compound, thus the charges are balanced. Cobalt can loose two electrons from its outermost shell and can become Cobalt (II) cation. Hydroxide has -1 charge and two atoms of hydroxide anions are present. Thus, overall charges are balanced in this way.