If the radius of an anion is double that of a cation,the coordination number of the cation and the type of hole occupied are respectively:

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

The structure of $Na_2O$ crystal is

The fraction of void space on the body diagonal in an ideal rock salt structure is [Use : $\sqrt{6} = 2.45$]

In a $NaCl$ crystal, the distance between $Na^{+}$ and $Cl^{-}$ ions is $a \ pm$. What is the edge length of the unit cell?

$A$ solid $AB$ has a $NaCl$ structure. $B$ atoms are at the corners and all face-centered positions of the unit cell,while $A$ atoms occupy all the $O.H.V.$ (Octahedral Voids). If all the atoms from the face-centered positions along one axis are removed,what will be the resulting stoichiometry of the solid?