The density of $NaCl$ is $2.165 \, g \, cm^{-3}$. The distance between $Na^+$ and $Cl^-$ ions in the $NaCl$ crystal is $281 \, pm$. Based on this information,the value of Avogadro's number is ...

The density of $Na$ is $0.613 \ g \ cm^{-3}$. If the edge length of the unit cell of $Na$ is $5 \ \mathring{A}$,the effective number of atoms of $Na$ per unit cell is (Atomic weight of $Na = 23 \ u$)

Gold has a cubic close-packed structure which can be viewed as spheres occupying $74\%$ of the total volume. What is the edge length of the unit cell if the density of gold is $19.3 \ g/cm^3$? $(Au = 197 \ amu)$

$A$ solid has a $bcc$ structure. If the distance of nearest approach between two atoms is $1.73 \, \mathring{A}$, the edge length of the cell is ........... $pm$.

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.
$N_{A} = 6.0 \times 10^{23} \ mol^{-1}$

If a metal crystallises in $bcc$ structure with edge length of unit cell $4.29 \times 10^{-8} \ cm$,the radius of the metal atom is: