What is the coordination number of a cation occupying an octahedral void?

Which of the following contains rock salt structure?

What is the total number of unit cells shared by each corner particle of a $bcc$ unit cell?

The radius of divalent cation $A^{+2}$ is $94 \, pm$ and divalent anion $B^{-2}$ is $146 \, pm$. The structure of compound $AB$ is

In an ionic crystal with the general formula $AX$,if the coordination number is $6$,what will be the value of the radius ratio?

An element crystallizes in a structure such that the unit cell is a cube with one atom at each corner and two atoms on its body diagonal. If the volume of this unit cell is $24 \times 10^{-24} \, cm^3$ and the density of the element is $7.2 \, g \, cm^{-3}$,calculate the number of atoms present in $200 \, g$ of the element.