In the calcium fluoride structure,the coordination number of the cation and anion are respectively:

$Pt$ has an $FCC$ structure with an edge length of unit cell $392 \text{ pm}$. What is the radius of $Pt$ (in $\text{ pm}$)?

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

The structure of $Na_2O$ crystal is

$A$ compound of $A$ and $B$ crystallises in a cubic lattice in which $A$ atoms occupy the lattice points at the corners of the cube. The $B$ atoms occupy the centre of each face of the cube. The probable empirical formula of the compound is

In an ${A^{+}}{B^{-}}$ ionic compound, the radii of ${A^{+}}$ and ${B^{-}}$ ions are $180 \ pm$ and $187 \ pm$ respectively. The crystal structure of this compound will be: