What is the number of unit cells present in $3.9 \ g$ of potassium if it crystallizes in $BCC$ structure?

What is the molar mass of a metal having a density of $8.57 \ g \ cm^{-3}$ and an edge length of $3.3 \ \mathring{A}$? (Packing efficiency $= 68 \%$)

$CsBr$ has $bcc$ structure with edge length $4.3 \ \mathring{A}$. The shortest interionic distance in between $Cs^{+}$ and $Br^{-}$ (in $\mathring{A}$) is :

Calculate the number of unit cells in $1 \text{ cm}^3$ of metal if it forms a simple cubic structure with a unit cell edge length of $500 \text{ pm}$.

$A$ metal crystallizes in two cubic phases,$fcc$ and $bcc$,whose unit cell edge lengths are $3.5 \ \mathring{A}$ and $3.0 \ \mathring{A}$ respectively. Calculate the ratio of the densities of $fcc$ and $bcc$ phases.

Calculate the molar mass of an element having a density of $8.6 \ g \ cm^{-3}$ if it forms a $bcc$ structure $[a^3 \times N_{A} = 22.0 \ cm^3 \ mol^{-1}]$.