$A$ solid $AB$ has a $ZnS$ type structure. If the radius of the $B^-$ ion is $100 \, pm$, what is the minimum radius of the $A^+$ cation in $pm$?

Argon crystallizes in such a way that the positions of the atoms are at $(0, 0, 0)$,$(0, 1/2, 1/2)$,$(1/2, 0, 1/2)$,and $(1/2, 1/2, 0)$. The type of unit cell is:

An alloy made up of $A$ and $B$ metals crystallises in a cubic lattice, where $B$ atoms occupy the corners and $A$ atoms occupy the face centers. The formula of the alloy formed is

For a tetrahedral structure,the limiting radius ratio $r_c^+ / r_a^-$ is .......

In the fluorite structure,the coordination number of the $Ca^{2+}$ ion is.....

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