Determine the number of vacancies per cubic meter occurring in $Cu$

at $100C,$ if $Cu$ has an $FCC$ lattice with lattice parameter of $0\mathrm{.}3615$

$nm$ and $83\mathrm{.}7K\frac{J}{?}$ mole of energy required to create vacancy. Atomic

wt$.$ of $Cu$ is $63\mathrm{.}5.$