Calculate the energy $($in eV$/$atom$)$ for vacancy formation in some metal, M $,$ given that the equilibrium number of vacancies at $571C$ is

$8\mathrm{.}74{10}^{23}{m}^{-3}.$ The density and atomic weight $($at $571C)$ for this metal are $14\mathrm{.}9\frac{g}{c}{m}^3$ and $89\mathrm{.}60\frac{g}{m}ol,$ respectively.

$Q_v=$

$e\frac{V}{?}$ atom