question_answer

The nearest distance between two atoms in case of a bcc lattice is equal to :

A) \[\frac{a\sqrt{2}}{3}\]                                   

B) \[\frac{a\sqrt{3}}{2}\]

C) \[a\sqrt{3}\]                                      

D) \[\frac{a}{\sqrt{2}}\]

Correct Answer: B

Solution :

                In a bcc lattice, the atoms touch one another along the body diagonal. For cube of length a and atomic radius r, we have                 \[r=\frac{\sqrt{3}}{4}a\] \[\therefore \]Distance between two atoms \[=\frac{2\times \sqrt{3}a}{4}\]                                                                 \[=\frac{\sqrt{3}}{2}a\]