What is the total number of particles present in a $bcc$ unit cell?

In the calcium fluoride structure,the coordination number of the cation and anion are respectively:

How many formula units are there in the unit cell of sodium chloride $(NaCl)$?

The radius of the calcium ion is $94 \text{ pm}$ and the radius of the oxide ion is $146 \text{ pm}$. What is the possible crystal structure of calcium oxide?

In a diamond crystal,each carbon atom is linked with other carbon atoms. The number of carbon atoms in a diamond unit cell is:

$A$ solid $AB$ crystallises in $NaCl$ structure. The anion $B$ forms $fcc$ lattice,while the cation $A^{+}$ occupies all the octahedral holes. If all the particles along a diagonal plane (as shown in the figure) are removed,then the formula of the solid becomes