Solution:
molar mass of zinc iodide = 319.22 g/mole
zinc = 1 (atom) x 65.38 g/mole = 65.38 g/mole
iodine = 2 (atoms) x 126.92 g/mole = 253.84 g/mole
[ (65.38 g/mole) / (319.22 g/mole) ] x 100 % = 20.48 %
0.50176 g / 1.94824 g = 0.2575452716 or 0.25755