THE WATER MOLECULE

Three-quarters of the surface of the earth is covered with water. While this is an impressive statistic, it is pale beside the spectacular photographs that have come to us from outer space.

They reveal a beautiful blue planet bathed in water, partly hidden by a veil of vapor. Life came into being in this water. As living things became more complex and specialized, they left the sea  or the land, taking water with them as the major part of their bodies.

On the Planet Earth, water is life.

A philosopher observed that the proper study of mankind is man; the water chemist paraphrases this: "The proper study of water is the water molecule." The formula for water—H2O—by itself tells us only its composition and molecular weight. It does nothing to explain the remarkable properties that result from its unique molecular arrangement. Two hydrogen atoms are located 105° apart, adjacent to the oxygen atom, so that the molecule is asymmetrical,

positively charged on the hydrogen side and negatively charged on the oxygen side. For this reason, water is said to be dipolar. This causes the molecules to agglomerate, the hydrogen of one molecule attracting the oxygen of a neighboring molecule. The linking of molecules resulting from this attractive force is called hydrogen bonding

One of the consequences of hydrogen bonding is that molecules Of H₂O cannot leave the surface of a body of water as readily as they could without this inter-molecular attraction. The energy required to rupture the hydrogen bond and liberate a molecule of H₂O to form vapor is much greater than for other common chemical compounds. Because of this fact, the water vapor—steam—has a high energy content and is an effective medium for transferring energy in industrial plant operations, buildings, and homes.