What is the nature of the Ca-Cl bond in a molecule of calcium chloride (CaCl2) if the electronegativity value of calcium is 1.0 and that of chlorine is 3.16?

CaCl2 has bonds that are mostly ionic in nature. The large difference in electronegativity values suggests these are strongly ionic. Of course, all bonds (except e.g. diatomic one, like F2, Cl2, O2, etc), have both ionic and covalent character to them. It just depends on which is favored.