$A$ substance forms a face-centered cubic $(FCC)$ crystal. Its density is $1.984 \ g \ cm^{-3}$ and the edge length of the unit cell is $630 \ pm$. Calculate the molar mass of the substance in $g \ mol^{-1}$.

Suppose the mass of a single $Ag$-atom is $m$. $Ag$ metal crystallises in $fcc$ lattice with unit cell of length $a$. The density of $Ag$ metal in terms of $a$ and $m$ is

$Na$ metal crystallizes in a $BCC$ structure. If the edge length of the unit cell is $4.29 \ \overset{o}{A}$,then the radius of the $Na$ atom is = ...... $cm$.

An element has a density of $6.8 \ g \ cm^{-3}$ and crystallizes in a $bcc$ structure with a unit cell edge length of $290 \ pm$. The number of atoms in $200 \ g$ of the element is:

Calculate the edge length of a unit cell that crystallizes to form a $BCC$ structure. (Radius of atom is $2.17 \times 10^{-8} \ cm$,$\sqrt{3} = 1.732$)

Ferrous oxide has a cubic structure and each edge of the unit cell is $5.0 \ \mathring{A}$. Assuming the density of the oxide is $4.0 \ g \ cm^{-3}$,calculate the number of $Fe^{2+}$ and $O^{2-}$ ions present in each unit cell ($M_w$ of $FeO = 72 \ g/mol$).