Calculate the number of unit cells in $1 \, g$ of $NaCl$ crystal,which crystallizes in an $fcc$ structure. (Molar mass of $NaCl = 58.5 \, g/mol$)

What is the edge length of the unit cell of a body-centred cubic $(BCC)$ crystal of an element whose atomic radius is $75 \ pm$ (in $pm$)?

Calculate the number of atoms present in $90 \text{ g}$ of a metal that forms a $bcc$ structure. Given: $[\rho \times a^3 = 1.8 \times 10^{-22} \text{ g}]$, where $\rho$ is density and $a$ is the edge length of the unit cell.

$KCl$ has the same structure as $NaCl$. If ${r_{Na^+}}/{r_{Cl^-}} = 0.5$ and ${r_{Na^+}}/{r_{K^+}} = 0.7$,then the ratio of the densities of $NaCl$ and $KCl$ will be .... (Molar mass $NaCl = 58.5 \, amu$,$KCl = 74.5 \, amu$)

Calculate the number of unit cells in $1 \, g$ of sodium metal that crystallizes in a $bcc$ structure. $(Na = 23 \, amu)$

An element (atomic weight $= 250 \ u$) crystallises in a simple cubic lattice. If the density of the unit cell is $7.2 \ g \ cm^{-3}$,what is the radius (in $\mathring{A}$) of the atom of the element? $(N_A = 6.02 \times 10^{23} \ mol^{-1})$