The atomic radius of strontium $(Sr)$ is $215 \, pm$ and it crystallises in a cubic closed packed $(ccp)$ structure. The edge length of the cube is .............. $pm$.

$KCl$ has the same structure as $NaCl$. If ${r_{Na^+}}/{r_{Cl^-}} = 0.5$ and ${r_{Na^+}}/{r_{K^+}} = 0.7$,then the ratio of the densities of $NaCl$ and $KCl$ will be .... (Molar mass $NaCl = 58.5 \, amu$,$KCl = 74.5 \, amu$)

Calculate the number of atoms present in $90 \text{ g}$ of a metal that forms a $bcc$ structure. Given: $[\rho \times a^3 = 1.8 \times 10^{-22} \text{ g}]$, where $\rho$ is density and $a$ is the edge length of the unit cell.

$Na$ metal crystallizes in a $BCC$ structure. If the edge length of the unit cell is $4.29 \ \overset{o}{A}$,then the radius of the $Na$ atom is = ...... $cm$.

In a $CsCl$ crystal,the interionic distance between $Cs^+$ and $Cl^-$ ions is:

Iron exhibits $bcc$ structure at room temperature. Above $900^{\circ}C$,it transforms to $fcc$ structure. The ratio of density of iron at room temperature to that at $900^{\circ}C$ (assuming molar mass and atomic radii of iron remains constant with temperature) is