Calculate the number of atoms present in 1.625 g metal if it forms bcc unit cell structure.
$[ \rho \times a^3 = 3.25 \times 10^{-22}\ \text{g}]$

Identify the covalent crystal from the following.

An element crystallises in fcc unit cell with cell edge length of $3.608 \times 10^{-8}$ cm, the density of element is $8.92 \text{ gcm}^{-3}$. Calculate the atomic mass of element ($\text{N}_A = 6.022 \times 10^{23}$).

Calculate the number of unit cells present in $1$ g metal if the product of the density of metal and the volume of unit cell is $2.5 \times 10^{-22}$ g.