Question

The coordination number of calcium fluoride type structure is (cation : anion) :

• A. $1:2$
• B. $4:4$
• C. $4:8$
• D. $8:4$

Answer 1

The correct option is D $8:4$

The coordination number of calcium fluoride ($Ca{F}_2$) type structure is $8:4$.
$C{a}^{2+}$ occupy face-centred cube and $F^{-}$ ions occupy all the tertrahedral voids.
The coordination number of $C{a}^{2+}$ is $8$ and the coordination number of $F^{-}$ ion is $4$.