In a face-centered cubic $(FCC)$ unit cell, if the edge length is $508 \text{ pm}$, what is the radius of the atom in $\text{pm}$?

$CsCl$ crystallises in a cubic structure that has $Cl^{-}$ at each corner and $Cs^{+}$ at the centre of the unit cell. If $r_{Cs^{+}} = 1.69 \ \mathring{A}$ and $r_{Cl^{-}} = 1.81 \ \mathring{A}$,what is the value of the edge length of the cube in $\mathring{A}$?

Calculate the edge length of $bcc$ unit cell if the radius of a particle present in it is $186 \ pm$.

Niobium crystallizes in a body-centered cubic $(BCC)$ structure. If the density is $8.55 \ g \ cm^{-3}$,calculate the atomic radius of niobium. (Atomic mass of niobium $M_w = 93 \ g \ mol^{-1}$)

Sodium metal crystallizes in a body-centered cubic $(BCC)$ lattice with a unit cell edge length of $4 \ \mathring{A}$. The radius of the sodium atom is $..... \times 10^{-1} \ \mathring{A}$ (Nearest integer).

The density of $KBr$ crystal is $2.75 \, g/cm^3$ and the edge length of the unit cell is $654 \, pm$. Calculate the number of formula units per unit cell and identify the type of unit cell. $(K = 39 \, u, Br = 80 \, u)$.