In calcium, fluoride having the florite structures. The coordination number for calcium ion `(Ca^(2+))` and fluoride ion `(F^(-))` are

Options

A. 4 and 2
B. 6 and 6
C. 8 and 4
D. 4 and 8

Answer

C

Explanation

In `CaF_(2)` (Fluorite structure), `Ca^(2+)` ions are arranged in ccp arrangement (`Ca^(2+)` ions are present at all corners and at the centre of each face of the cube) while `F^(-)` ions occupy all the tetrahedral sites.

From the above figure, you can clearly see that coordination number of `f^(-)` is 4 while that of `Ca^(2+)` is 8.