question_answer

The distance between the body centred atom and a corner atom in sodium \[(a=4.225{AA})\] is          [CBSE PMT 1995]

A) \[3.66\,{AA}\]                    

B) \[3.17\,{AA}\]

C) \[2.99\,{AA}\]                    

D) \[2.54\,{AA}\]

Correct Answer: A

Solution :

Sodium has bcc structure. The distance between body centre and a  corner \[=\frac{\sqrt{3}\,a}{2}\] \[=\frac{\sqrt{3}\times 4.225}{2}=3.66\,{AA}\]