Calculate the volume occupied by a particle in bcc unit cell if the volume of unit cell is $8.2 \times 10^{-23} \mathrm{~cm}^3$.

Calculate the number of unit cells in $1 \mathrm{~cm}^3$ volume of an element if unit cell edge length is $4.0 \times 10^{-8} \mathrm{~cm}$.

Which of the following dopants is used in germanium to form n-type semiconductor?

Identify the type of defect from following in stainless steel.