If an element having atomic number $96$ crystallises in a cubic lattice with a density of $10.3 \ g \ cm^{-3}$ and an edge length of $314 \ pm$, then the structure of the solid is:

$A$ metal crystallises in $bcc$ lattice with unit cell edge length of $300 \ pm$ and density $6.15 \ g \ cm^{-3}$. The molar mass of the metal is

$CsCl$ has a $bcc$ arrangement. Its unit cell edge length is $400 \, pm$. What is its inter-ionic distance?

Salt $AB$ has a zinc blende structure. The radii of $A^{2+}$ and $B^{2-}$ ions are $0.7 \ \mathring{A}$ and $1.8 \ \mathring{A}$ respectively. The edge length of the $AB$ unit cell is ........... $\mathring{A}$.

Calculate the number of atoms in $20 \ g$ of a metal which crystallizes in a simple cubic structure with a unit cell edge length of $340 \ pm$. (Density of metal $= 9.8 \ g \ cm^{-3}$)

$A$ metal crystallises in two phases,one as $fcc$ and other as $bcc$ with unit cell edge lengths of $3.5 \ \mathring{A}$ and $3.0 \ \mathring{A}$ respectively. The ratio of density of $fcc$ and $bcc$ phases approximately is