Question

In `A^(=)B^(-)` ionic compound radii of `A^(=) and B^(-)` ions are `180 pm ` and `187 pm` respectively .The crystal structure of this compound will be
A. `NaCI` type
B. `CaCI` type
C. `ZnS` type
D. Similar to diamond

Answer 1

Correct Answer - b
`r_(+) // r_(-) = (180)/(187) = 0.962 `which lies in the range of `0.732 - 1.000` hence coordination number `= 8 `i.e. the structure is `CaCI` type.