$Xe$ crystallizes in an $FCC$ structure. The edge length of its unit cell is $620 \, pm$. The radius of $Xe$ is $=$ ...... $pm$.

Calculate the number of unit cells in $3 \ g$ of a metal that crystallises in a simple cubic unit cell with an edge length of $336 \ pm$. (Density of metal $= 9.4 \ g \ cm^{-3}$)

If a metal crystallises in $bcc$ structure with edge length of unit cell $4.29 \times 10^{-8} \ cm$,the radius of the metal atom is:

The volume of a simple cubic unit cell is $x \times 10^{-23} \ cm^3$. Calculate the value of $x$ if the volume occupied by a particle in it is $2.1 \times 10^{-23} \ cm^3$.

For a crystal,the diffraction angle for the second-order diffraction is $2\theta = 90^{\circ}$. If the distance between two parallel planes is $2.28 \ \mathring{A}$,then the wavelength of the $X$-rays used for Bragg diffraction (in $\mathring{A}$) will be .........

Sodium metal crystallizes in a body-centered cubic $(BCC)$ lattice with a unit cell edge length of $4 \ \mathring{A}$. The radius of the sodium atom is $..... \times 10^{-1} \ \mathring{A}$ (Nearest integer).