Consider the crystal structure of sodium chloride which is modeled as a set of touching spheres. each sodium atom has a radius and each chlorine atom has a radi

Consider the crystal structure of sodium chloride which is modeled as a set of touching spheres. Each sodium atom has a radius and each chlorine atom has a radius r. The centres of the spheres from a simple cubic lattice. The packing fraction of this system is 27 + (c)t +r (d) * " 2, +)