Lithium has a body-centered cubic $(BCC)$ structure. If the edge length of its unit cell is $351 \ pm$, what is the atomic radius of lithium in $pm$?

$A$ metal crystallizes in a $BCC$ structure. The edge length of its unit cell is $3.04 \ \mathring{A}$. What is the volume of its unit cell in $cm^3$?

An element crystallises in an $fcc$ unit cell with a cell edge length of $3.608 \times 10^{-8} \text{ cm}$. The density of the element is $8.92 \text{ g cm}^{-3}$. Calculate the atomic mass of the element $(N_A = 6.022 \times 10^{23} \text{ mol}^{-1})$. (in $\text{ g/mol}$)

The diffraction pattern of a crystalline solid gave a peak at $2 \theta = 60^{\circ}$. What is the distance (in $cm$) between the layers which gave this peak? ($\lambda$ of $X$-rays is $1.54 \mathring{A}$) ($\sin 30^{\circ} = 0.5$,$\sin 60^{\circ} = 0.866$; $n = 1$)

What is the molar mass of a metal with a $BCC$ structure having a density of $10 \ g \ cm^{-3}$ and an edge length of $200 \ pm$?

In a $NaCl$ crystal,the distance between $Na^+$ and $Cl^-$ ions is $2.814 \ \overset{\circ}{A}$ and the density of the crystal is $2.167 \ g/cm^3$. Calculate the value of Avogadro's number $(N_A)$.