The ratio of anion radius to cation radius of a crystal is $10 : 9.3$. Then,the coordination number of the cation in the crystal is

What is the coordination number of the $Ca^{2+}$ ion in the fluorite structure?

In the zinc blende structure,zinc atoms fill up:

For an ionic crystal of the type $AB$,the value of the limiting radius ratio is $0.40$. This value suggests that the crystal structure should be:

The radius of the calcium ion is $94 \text{ pm}$ and the radius of the oxide ion is $146 \text{ pm}$. What is the possible crystal structure of calcium oxide?

In a face-centred cubic $(FCC)$ lattice,atoms of $A$ form the corner points and atoms of $B$ form the face-centred points. If two atoms of $A$ are missing from the corner points,the formula of the ionic compound is