The number of $Cl^{-}$ ions around one $Na^{+}$ in $NaCl$ crystal lattice is

The coordination number of a cation occupying a tetrahedral hole is

Explain the calculation of the number of atoms in a primitive cubic unit cell.

In the face-centred cubic $(FCC)$ lattice structure of gold, the closest distance between gold atoms is ('a' being the edge length of the cubic unit cell).

In a solid $AB$ having the $NaCl$ structure,$A$ atoms occupy the corners of the cubic unit cell. If all the face-centered atoms along one of the axes are removed,then the resultant stoichiometry of the solid is

If the side length of a face-centered cubic $(fcc)$ unit cell of a metal is $400 \ pm$, the approximate radius of the metal atom in $pm$ is $(\sqrt{2} = 1.414)$.