Consider Face Centered Cubic $($FCC$)$ Silver $($Ag$)$ crystal structure with an atomic radius $r_{Ag}=0\mathrm{.}172nm.$ The side of the cubic unit cell is a $=0\mathrm{.}486nm.$

The linear density along $[101]$ is $$ atoms$/$nm

The linear density along $[111]$ is $$ atoms$/$nm

The planar density in the plane $(100)$ is $$ atoms $\frac{?}{n{m}^2}$

The planar density in the plane $(111)$ is $$ atoms $\frac{?}{n{m}^2}$