Sodium crystallises in $bcc$ structure with radius $1.86 \times 10^{-8} \ cm$. Calculate the edge length of the unit cell.

$A$ metal crystallises in two phases,one as $fcc$ and other as $bcc$ with unit cell edge lengths of $3.5 \ \mathring{A}$ and $3.0 \ \mathring{A}$ respectively. The ratio of density of $fcc$ and $bcc$ phases approximately is

An element $A$ has a face-centred cubic $(fcc)$ structure with an edge length equal to $361 \ pm$. The radius of atom $A$ is ............... $pm$.

Aluminium crystallises in a face-centred cubic structure, its atomic radius is $125 \text{ pm}$. What is the edge length of the unit cell (in $\text{pm}$)?

Calculate the number of unit cells in $1 \ cm^3$ volume of an element if unit cell edge length is $4.0 \times 10^{-8} \ cm$.

An element has a crystalline structure where the unit cell is a cube with one atom at each corner and two atoms on its body diagonal. If the volume of this unit cell is $24 \times 10^{-24} \, cm^3$ and the density of the element is $7.2 \, g \, cm^{-3}$,then the number of atoms present in $200 \, g$ of the element is: