It is given as a face$-$centered cubic structure with a Lattice constant of $40A$

meters$).$ calculate the density of atoms of unit length in the $\left[\begin{array}{ccc}1& 1& 0\end{array}\right]$

direction.

A$.$

$1\mathrm{.}5{10}^{+7}$ato$\frac{m}{c}m$

B$.$

$3\mathrm{.}5{10}^{+7}$ atom $\frac{?}{cm}$

c$.$

$0\mathrm{.}5{10}^{+7}$ato$\frac{m}{c}m$

D$.4\mathrm{.}5{10}^{+7}$ato$\frac{m}{c}m$

E$.2\mathrm{.}5{10}^{+7}$ato$\frac{m}{c}m$