What is the coordination number of a particle in $fcc$ structure?

The face diagonal length of $f.c.c.$ cubic cell is $660 \sqrt{2} \, pm$. If the radius of the cation is $110 \, pm$,the radius of the anion is ............ $pm$.

An element has a $bcc$ structure with $12.08 \times 10^{23}$ unit cells. What is the total number of atoms in these unit cells?

If the radius ratio for an ionic solid is $0.5248$ and the radius of the cation is $0.95 \ \mathring{A}$,what is the radius of the anion?

The number of unit cells present in $39 \ g$ of potassium if it crystallizes as a body-centered cubic $(BCC)$ structure is ($N = \text{Avogadro number}$, $\text{At. wt. of potassium} = 39$).

If $a$ is the length of the side of a cube,the distance between the body-centered atom and one corner atom in the cube will be