$A$ given metal crystallises out with a cubic structure having edge length of $361 \, pm$. If there are four metal atoms in one unit cell,what is the radius of one atom? .............. $pm$

Iron oxide $FeO$ crystallises in a cubic lattice with a unit cell edge length of $5.0 \ \mathring{A}$. If the density of the $FeO$ in the crystal is $4.0 \ g \ cm^{-3}$,then the number of $FeO$ units present per unit cell is $...........$ (Nearest integer).
Given: Molar mass of $Fe$ and $O$ is $56$ and $16 \ g \ mol^{-1}$ respectively.
$N_{A} = 6.0 \times 10^{23} \ mol^{-1}$

What is the number of atoms in $1000 \ g$ of an $FCC$ crystal? Given density $= 10 \ g \ cm^{-3}$ and edge length $= 200 \ pm$.

An element with molar mass $2.7 \times 10^{-2} \ kg \ mol^{-1}$ forms a cubic unit cell with edge length $405 \ pm$. If its density is $2.7 \times 10^{3} \ kg \ m^{-3},$ the radius of the element is approximately......... $\times 10^{-12} \ m$ (to the nearest integer).

An element crystallizes in an $fcc$ structure with an edge length of $200 \, pm$. If $200 \, g$ of this element contains $24 \times 10^{23}$ atoms,calculate its density in $g \, cm^{-3}$.

Calculate the molar mass of an element with density $2.7 \ g \ cm^{-3}$ that forms $fcc$ structure. $\left[a^3 \cdot N_{A}=40 \ cm^3 \ mol^{-1}\right]$