An element has a body-centered cubic $(bcc)$ structure with a cell edge of $288 \ pm$. The atomic radius is $...... \ pm$.

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 $= 9.8 \ g \ cm^{-3}$)

Copper crystallises in $fcc$ with a unit cell length of $361 \ pm$. What is the radius of copper atom? ............... $pm$

$Na$ 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 = ...... $cm$.

Calculate the edge length of $bcc$ unit cell if the radius of a particle present in it is $186 \ pm$.

An element has a crystalline structure where the unit cell is a cube with one atom at each corner and two atoms on its body diagonal. If the volume of this unit cell is $24 \times 10^{-24} \, cm^3$ and the density of the element is $7.2 \, g \, cm^{-3}$,then the number of atoms present in $200 \, g$ of the element is: