$A$ metal crystallizes in a simple cubic lattice. The radius of the metal atom is $x \ pm$. What is the volume of the unit cell in $pm^3$?

$A$ metal crystallizes with a $FCC$ lattice, the edge of whose unit cell is $x \text{ pm}$. The diameter of this metal atom would be $\text{pm}$.

The formula for the determination of the density of a unit cell is:

Xenon crystallizes in $fcc$ lattice and the edge length of unit cell is $620 \ pm$. What is the radius of $Xe$ atom (in $pm$)?

Calculate the number of atoms present in a unit cell for an element having a molar mass of $23 \ g \ mol^{-1}$ and a density of $0.96 \ g \ cm^{-3}$. Given that $a^3 \cdot N_{A} = 48 \ cm^3 \ mol^{-1}$.

$A$ metal crystallizes in two cubic phases,$fcc$ and $bcc$,whose unit cell edge lengths are $3.5 \ \mathring{A}$ and $3.0 \ \mathring{A}$ respectively. Calculate the ratio of the densities of $fcc$ and $bcc$ phases.