Calculate the molar mass of a metal with density $1 \ g \ cm^{-3}$ forming a $bcc$ structure with an edge length of $420 \ pm$.

Sodium metal crystallizes in $B.C.C.$ lattice with an edge length of $4.29 \ \mathring{A}$. The radius of the sodium atom is:

Calculate the number of unit cells in $0.79 \ g$ of a metal if the product of the density and the volume of the unit cell is $1.58 \times 10^{-22} \ g$.

What is the number of unit cells present in $3.9 \ g$ of potassium if it crystallizes in $BCC$ structure?

Copper crystallises in $fcc$ unit cell with cell edge length of $3.608 \times 10^{-8} \, cm$. The density of copper is $8.92 \, g \, cm^{-3}$. Calculate the atomic mass of copper. (In $u$)

In the $x$-ray reflection $(n=1)$, the distance between two parallel planes of $NaCl$ is $280 \ pm$ and the diffraction angle is $5.2^{\circ}$. What is the wavelength of its light radiation? (Given: $\sin 5.2^{\circ} = 0.09$)