The edge length of an $FCC$ unit cell is given by:

$KBr$ has $NaCl$ structure. Its density is $2.75 \ g \ cm^{-3}$. The edge length of the unit cell will be (molar mass of $KBr$ is $119 \ g \ mol^{-1}$):

Copper crystallizes in an $fcc$ lattice with an edge length of $3.61 \times 10^{-8} \, cm$. If the measured density is $8.92 \, g \, cm^{-3}$,calculate the theoretical density of the crystal in $g \, cm^{-3}$. (Atomic mass of $Cu = 63.5 \, g \, mol^{-1}$)

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

What is the edge length of the unit cell of a body-centred cubic $(BCC)$ crystal of an element whose atomic radius is $75 \ pm$ (in $pm$)?

Calculate the distance between two parallel $(220)$ planes in a crystal with an edge length of $450 \, pm$. (in $pm$)