In an $NaCl$ crystal, the radii of $Na^{+}$ and $Cl^{-}$ ions are $95 \, pm$ and $180 \, pm$ respectively. The edge length of its unit cell is ........... $pm$.

An element crystallises in an $fcc$ unit cell with a cell edge length of $3.608 \times 10^{-8} \text{ cm}$. The density of the element is $8.92 \text{ g cm}^{-3}$. Calculate the atomic mass of the element $(N_A = 6.022 \times 10^{23} \text{ mol}^{-1})$. (in $\text{ g/mol}$)

Gold (edge length $0.144 \ nm$) crystallizes in a face-centered cubic unit cell. What is the radius $(r)$ of the gold atom in $pm$?

What is the number of unit cells present in $3.9 \ g$ of potassium if it crystallizes in $BCC$ structure?

The cubic unit cell of aluminium (Molar mass $27.0 \ g \ mol^{-1}$) has an edge length of $405 \ pm$. Its density is $2.70 \ g \ cm^{-3}$. The type of unit cell is

Calculate the density of an element having molar mass $27 \ g \ mol^{-1}$ that forms $fcc$ unit cell. $[a^3 \cdot N_A = 38.5 \ cm^3 \ mol^{-1}]$ (in $g \ cm^{-3}$)