Xenon crystallizes in $fcc$ lattice and the edge length of unit cell is $620 \ pm$. What is the radius of $Xe$ atom (in $pm$)?

An element crystallises in a $fcc$ lattice with cell edge $250 \ pm$. Calculate the density of the element (atomic mass $= 90.3 \ g \ mol^{-1}$) (in $g \ cm^{-3}$)

Calculate the number of unit cells in $58.5 \, g$ of $NaCl$ crystallizing in an $fcc$ structure. $(NaCl = 58.5 \, g/mol)$

$A$ solid having density of $9 \times 10^3 \ kg \ m^{-3}$ forms face-centred cubic crystals of edge length $200 \sqrt{2} \ pm$. What is the molar mass of the solid? [Avogadro constant $\cong 6 \times 10^{23} \ mol^{-1}$,$\pi \cong 3$]

Calculate the density of a metal having a molar mass of $210 \ g \ mol^{-1}$ that forms a simple cubic unit cell. $(a^3 \cdot N_{A} = 21.5 \ cm^3 \ mol^{-1})$ (in $g \ cm^{-3}$)

$KBr$ has a rock salt type structure and has a density of $3.70 \ g/cm^3$. The edge length of the unit cell is approximately [molecular weight of $KBr = 120 \ g/mol$]: