What is the number of atoms per unit cell in a face-centered cubic $(FCC)$ crystal lattice?

What is the coordination number of $Zn^{2+}$ and $S^{2-}$ ions in the zinc blende $(ZnS)$ structure?

If the distance between $Na^{+}$ and $Cl^{-}$ ions in sodium chloride crystal is $X \ pm$, the length of the edge of the unit cell is

What is the coordination number of a cation occupying an octahedral void?

The crystal $AB$ has a structure similar to $NaCl$. Atoms of $A$ are present at each corner of the cubic unit cell. If all atoms along one of the axes passing through the face centers are removed,what will be the resulting stoichiometry?

How many unit cells are present in $39 \ g$ of potassium that crystallizes in a body-centered cubic $(BCC)$ structure? [Atomic weight of $K = 39$]