Question

The distance in pico metres between centres of two closest sodium atoms centred cubic lattice of sodium metal with a unit cell length of 4.3 $\mathring{A}$ is :

• A. 372
• B. 328
• C. 256
• D. 214

Answer 1

Answer: (A)

372

Given :

$4.3A^o=430pm$

Sodium forms body centred cubic lattice. The distance in pico metres between centres of two closest sodium atoms :

$=\frac{\sqrt{3}}{2}a=\frac{\sqrt{3}}{2}\times 430=372pm$

Hence the correct option is A.