Lithium Chloride Crystallizes in a Face-Centered Cubic Structure

Lithium chloride crystallizes in a face-centered cubic structure.The unit cell length is 5.14 × 10^-8 cm.The chloride ions are touching each other along the face diagonal of the unit cell.The lithium ions fit into the holes between the chloride ions.What is the mass of Li Cl in a unit cell?

A) 5.63 × 10^-22 g
B) 1.41 × 10^-22 g
C) 4.22 × 10^-22 g
D) 7.04 × 10^-23 g
E) 2.82 × 10^-22 g