The packing efficiency and coordination number of face-centred cubic $(FCC)$ lattice is

In $F.C.C.$,each face of the unit cell is shared equally by how many unit cells?

If three elements $A, B, C$ crystallize in a cubic solid lattice with $B$ atoms at the cubic centers, $C$ atoms at the center of edges, and $A$ atoms at the corners, then the formula of the compound is

What is the coordination number in a calcium fluoride $(CaF_2)$ type structure?

The coordination number of a metal crystallizing in a hexagonal close packed structure is

If the distance between $Na^{+}$ and $Cl^{-}$ ions in $NaCl$ crystal is $a \, pm$, what is the length of the cell edge?