The number of neutrons in the dipositive zinc ion

When two electrons are loss from zinc atom then dispositive ${\text{Zn}}^{+2}$ is formed

$\text{Atomic number of zinc,(Zn),Z}=30$ 

Mass number of zinc $\text{A}=65$      

$\text{No.of neutrons of zinc, n}=\text{A}-\text{Z}$

                                         $=65-30$

                                         $=35$