Which of the following statement(s) is (are) correct for `CaF_(2)`, 

Options

A. `Ca^(2+)` ions are present only at the corners of a cube
B. c.c.p. type structure
C. `F^(-)` ions are present in all the octahedral voids
D. The structrue has `8 : 4` co-ordination number

Answer

B, D

Explanation

`Ca^(+2)` is in the FCC lattice F ions are present at the Tetrahcdral voids. Co-ordinatior number of `Ca^(+2)` is 8 and that of `F^(-)` is 4