The crystal structure of $NaCl$ is:

Which among the following crystal lattices occupies all of the cubic holes by cations?

Copper crystallizes in $f.c.c.$ with a unit cell length of $361 \ pm$. What is the radius of copper atom? (in $pm$)

The correct coordination number for the zinc ion in the zinc blende crystal structure is:

An ionic compound $AB$ has $ZnS$ type structure. If the radius of $A^{+}$ is $22.5 \ pm$, then the ideal radius of $B^{-}$ would be .............. $pm$.

In a face-centered cubic lattice of $X$ and $Y$ atoms,$X$ atoms are present at the corners while $Y$ atoms are at the face centers. If two atoms of $X$ are missing from the corners,what is the formula of the compound?