two different questions:
(1): give an example of the formation of an ionic compound from its elements.
(2): why is the presence of a dipole moment in the water molecue so imporant? What are some properties of water that are determined by its polarity?
1. sodium metal reacts (burns) in chlorine gas forming sodium chloride, NaCl.
2. The ability of water to dissolve ionic solids (most salts) and polar molecular compounds (sugars, alcohols, ammonia, etc) is because of its polarity and its ability to form "hydrogen bonds". All physical and chemical properties of water which are so important to living things and their environment, are related to its molecular dipole.