Question

What is the C.N of `Ca^(2+)` and `F^(-)` ions in `CaF_(2)` crystal lattice ?
A. C.N of `Ca^(2+)=4` and `F^(-)=8`
B. C.N of `Ca^(2+)=6` and `F^(-)=6`
C. C.N of `Ca^(2+)=8` and `F^(-)=8`
D. C.N of `Ca^(2+)=8` and `F^(-)=4`

Answer 1

Correct Answer - D
Each `Ca^(2+)` ion is surrounded by `8F^(-)` ions and `F^(-)` ion by `4Ca^(2+)` ions. Thus, the C.N. of `Ca^(2+)=8` and of `F^(-)=4` in `CaF_(2)`