Question

Which of the following expression is correct for a CsCl unit cell with lattice parameter,a?
A. `r_(cs+)+r_(cl^(-))=2a`
B. `r_(cs+)+r_(cl^(-))=(a)/(sqrt2)`
C. `r_(cs+)+r_(cl^(-))=(sqrt3)/(2)a`
D. `r_(cs+)+r_(cl^(-))=(3)/(2)a`

Answer 1

(c ) CsCl crystal has bcc structure,
` Rightarrow r_(Cs)+r_(Cl^(-))+(sqrt3)/(2)a`