An element crystallising in $fcc$ lattice has a density of $8.92 \ g \ cm^{-3}$ and edge length of $3.61 \times 10^{-8} \ cm$. What is the atomic weight of the element (in $u$)? $(N_A = 6.022 \times 10^{23} \ mol^{-1})$

Calculate the edge length of $fcc$ unit cell if the radius of the metal atom is $139 \ pm$.

An $X^{+}Y^{-}$ ionic compound has a $bcc$ structure. The distance between two nearest ions is $1.73 \ \mathring{A}$. What is the edge length of the unit cell?

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 $pm$?

How can you determine the atomic mass of an unknown metal if you know its density and the dimension of its unit cell? Explain.

Radius of cation and anion are $2.5 \ \mathring{A}$ and $2.6 \ \mathring{A}$ respectively. If a cubic crystal system is prepared by combination of above cation and anion then edge length of unit cell is ................ $\mathring{A}$ (Take $\sqrt{3} = 1.7$)