In `CaF_(2)` type (fluorite structure) `Ca^(2+)` ions form W structure and `F^(-)` ions are present in all X voids. The coordination number of `Ca^(2=)` is Y and `F^(-)` is Z. W,X,Y and Z respectively are

Options

A. W-ccp,X-octahedral,Y-8,Z-4
B. W-bcc,X-tetrahedral,Y-4,Z-8
C. W-ccp,X-tetrahedral,Y-8,Z-4
D. W-ccp,X-octahedral,Y-4,Z-8

Answer

C

Explanation

`Ca^(2+)` ions form ccp structure while `F^(-)` ions are in all tetrahedral holes and coordination number are 8 and 4.