An element crystallises in fcc type of unit cell. The volume of one unit cell is $24.99 \times 10^{-24} \mathrm{~cm}^3$ and density of the element $7.2 \mathrm{~g} \mathrm{~cm}^{-3}$. Calculate the number of unit cells in 36 g of pure sample of element?

What is the percentage of unoccupied space in fcc unit cell?

Which among the following crystal lattices occupies all of the cubic holes by cations?

Silver crystallises in fcc structure, if edge length of unit cell is 316.5 pm . What is the radius of silver atom?