Chemistry - Solid State Question with Solution | TestHub

The mass of one unit cell is given by $\rho \times a^3=6.8\times 10^{-22}\text{ g}$.

For an fcc unit cell, the number of atoms per unit cell is $Z=4$.

The mass of one atom is $\frac{\rho \times a^3}{Z}=\frac{6.8\times 10^{-22}}{4}=1.7\times 10^{-22}\text{ g}$.

The number of atoms in $1\text{ g}$ of the element is $\frac{1}{1.7\times 10^{-22}}=5.882\times 10^{21}$.

Answer: $5.882\times 10^{21}$