What is the total number of ions present in one unit cell of sodium chloride lattice?

What is the nature of octahedral holes (voids)?

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

The coordination number of a metal crystallizing in a hexagonal close-packed $(hcp)$ structure is:

$A$ solid has a structure in which $W$ atoms are located at the corners of a cubic lattice, oxygen atoms at the edge centres, and $Na$ atoms at the body centre. The formula of the compound is:

$A^{+}B^{-}$ shows rock salt type arrangement. Edge length of unit cell is $6 \ \mathring{A}$. If radius of $A^{+}$ is $1 \ \mathring{A}$,then the incorrect option is: