Which of the following expression is correct in case of a CsCl unit cell (edge length, a)?

Options

A. `r_(c)+r_(a)=a`
B. `r_(c)+r_(a)=(a)/(sqrt(2))`
C. `r_(c)+r_(a)=(sqrt(3)a)/(2)`
D. `r_(c)+r_(a)=(a)/(2)`

Answer

C

Explanation

CaCl crystal is body- centred cubic unit cell.
Hence. `2r_(c)+2r_(a)=sqrt(3)a:.r_(c)+r_(a)=(sqrt(3))/(sqrt(2))a`