In an $NaCl$ crystal,how many $Cl^{-}$ ions surround each $Na^{+}$ ion?

The edge lengths of a simple cubic $(sc)$ and a face-centered cubic $(fcc)$ unit cell are equal. The ratio of the volume occupied by atoms in these two structures is .....

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

$A$ compound formed by elements $X$ and $Y$ crystallises in a cubic structure, where $X$ atoms are at the corners of a cube and $Y$ atoms are at the body centre. The formula of the compound 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

Calculate the total volume occupied by all atoms in a simple cubic unit cell if the radius of the atom is $3 \times 10^{-8} \ cm$.