The crystal structure of $NaCl$ is:

$A$ solid $A^{+}B^{-}$ has a $NaCl$ type close-packed structure. If the radius of the anion is $250 \ pm$, what should be the ideal radius of the cation in $pm$?

In a compound,$W$ atoms are at the corners of the unit cell,$O$ atoms are at the edges of the unit cell,and $Na$ atoms are at the body center. The molecular formula of the compound is:

Potassium fluoride $(KF)$ has a $NaCl$ type structure. If the edge length of the unit cell is $a$,what is the distance between $K^+$ and $F^-$ ions?

An ionic compound has a unit cell consisting of $A$ ions at the corners of a cube and $B$ ions on the centres of the faces of the cube. The empirical formula for this compound would be

The number of spheres contained $(i)$ in one body centred cubic unit cell and $(ii)$ in one face centred cubic unit cell,is