The number of atoms in 4.5 g of a face-centred cubic crystal with edge length 300 pm is (Given : Density $=10 \mathrm{~g} \mathrm{~cm}^{-3}$ and $N_A=6.022 \times 10^{23}$)

If '$$a$$' stands for the edge length of the cubic systems. The ratio of radii in simple cubic, body centred cubic and face centred cubic unit cells is

Match the column A (type of crystalline solid) with the column B (example for each type)

A metal crystallises in a body centred cubic lattice with the metallic radius $$\sqrt3\mathop A\limits^o $$. The volume of the unit cell in $$\mathrm{m}^3$$ is