Calculate the number of atoms present in $1 \ g$ of an element if it forms an $fcc$ unit cell structure. [ $\varrho \times a^3 = 6.8 \times 10^{-22} \ g$ ]

The distance between $Na^{+}$ and $Cl^{-}$ ions in solid $NaCl$ of density $2.165 \ g \ cm^{-3}$ is $........ \times 10^{-10} \ m$. (Nearest Integer)
(Given : $N_{A} = 6.02 \times 10^{23} \ mol^{-1}$,Molar mass of $NaCl = 58.5 \ g \ mol^{-1}$)

An element has an $fcc$ structure. If its edge length is $200 \, pm$, calculate the density of this element having a mass of $200 \, g$. $[200 \, g$ of the element contains $24 \times 10^{23}$ atoms.$]$

Calculate the number of atoms in $1 \ g$ of a metal if it forms an $fcc$ crystal structure,given that $\varrho \times a^3 = 1.728 \times 10^{-22} \ g$.

$CsBr$ has $b.c.c.$ structure with edge length $4.3 \ \mathring{A}$. The shortest inter-ionic distance between $Cs^{+}$ and $Br^{-}$ is ........... $\mathring{A}$.

$A$ metal has a $fcc$ lattice. The edge length of the unit cell is $404 \, pm$. The density of the metal is $2.72 \, g \, cm^{-3}$. The molar mass of the metal is ................. $g \, mol^{-1}$.
($N_A$ Avogadro's constant $= 6.02 \times 10^{23} \, mol^{-1}$)