Which of the following instruments is used to determine the crystal structure?

The edge length of a unit cell of a metal having a molar mass of $75 \ g/mol$ is $5 \ \mathring{A}$. It crystallizes in a cubic lattice. If the density is $2 \ g/cm^3$, find the radius of the metal atom in $pm$. (Given: $N_A = 6 \times 10^{23}$)

Calculate the number of atoms in $1 \text{ g}$ of a metal that forms a $bcc$ crystal structure. Given that the product of density and unit cell volume is $\rho \times a^3 = 6.6 \times 10^{-22} \text{ g}$.

Calculate the number of unit cells in $0.79 \ g$ of a metal if the product of the density and the volume of the unit cell is $1.58 \times 10^{-22} \ g$.

Which formula is used to calculate edge length $(a)$ in a $bcc$ structure,where $r$ is the radius of the atom?

$A$ compound has $fcc$ structure. If the density of the unit cell is $3.4 \text{ g cm}^{-3}$,what is the edge length of the unit cell? (Molar mass $= 98.99 \text{ g mol}^{-1}$)