$A$ metal crystallizes in two phases,one as $fcc$ and another 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

An element has an $fcc$ structure. If $200 \ g$ of this element contains $4.12 \times 10^{24}$ atoms and the density of the element is $7.2 \ g \ cm^{-3}$, calculate the edge length of the unit cell.

Select the $INCORRECT$ option regarding the cubic crystal system-

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:

The inter-planar spacing between the $(2, 2, 1)$ planes of a cubic lattice of length $450 \, pm$ is $.... \, pm$

An element with molar mass $2.7 \times 10^{-2} \ kg \ mol^{-1}$ forms a cubic unit cell with edge length $405 \ pm$. If its density is $2.7 \times 10^{3} \ kg \ m^{-3},$ the radius of the element is approximately......... $\times 10^{-12} \ m$ (to the nearest integer).