Question

The inter-planar spacing between the $(221)$ planes of a cubic lattice of length $450pm$ is

• A. 50 pm
• B. 150 pm
• C. 300 pm
• D. 450 pm

Answer 1

Answer: (B)

Interplanar distance,
$d=\frac{a}{\sqrt{h^2+k^2+l^2}}$
Given, length of cubic lattice = $450pm$
For $(221)$ plane,
$h=2,$
$k=2,$
$l=l$
$\therefore d=\frac{450}{\sqrt{{\left(2\right)}^2+{\left(2\right)}^2+{\left(1\right)}^2}}$
$=\frac{450}{\sqrt{9}}=\frac{450}{3}=150pm$