Calculate the number of atoms in 0.4 gram of metal if it forms fcc structure.

$$ \left[\rho \times \mathrm{a}^3=1.2 \times 10^{-22} \mathrm{~g}\right] $$

Calculate the molar mass of an element having density $19.2 \mathrm{~g} \mathrm{~cm}^{-3}$ if it forms fcc structure $\left[\mathrm{a}^3 \times \mathrm{N}_{\mathrm{A}}=40 \mathrm{~cm}^3 \mathrm{~mol}^{-1}\right]$

Calculate the volume occupied by particle in simple cubic unit cell if volume of unit cell is $5.5 \times 10^{-22} \mathrm{~cm}^3$.