Question

An element crystallises in body-centred cubic structure. If the edge length of the cubic unit cell is 400 pm, the interatomic distance in the crystal is ______.

Options

• 346.4 pm

• 282.8 pm

• 400 pm

• 200 pm

Answer 1

An element crystallises in body-centred cubic structure. If the edge length of the cubic unit cell is 400 pm, the interatomic distance in the crystal is 346.4 pm.

Explanation:

Given: Edge length (a) = 400 pm

In bcc,

Nearest neighbour distance = `sqrt 3/2 xx a`

= `sqrt 3/2 xx 400`

= `(1.732 xx 400)/2`

= `692.8/2`

= 346.4 pm