Question

An element E crystallize in bcc. If the edge length of cell is 1.469×10-10 m and the density is 19.3g cm, calculate the atomic mass of the element and radius of atoms of element

Answer 1

bcc str has 2 atoms per unit cell.

so Z=2

edge length(a)=1.469×10^-10

Let atomic mass=M

density=Z×M÷a^3×N (N=Avogadro no)

>19.3=2×M×1.67×10^-24÷(1.469)^3×10^-24 [here 1/N=1.67×10^-24 cm]

>M=18.318