A Darke County Tale

| September/October 1994

735 Riddle Road Cincinnati, Ohio 45220

I'm a molecule of water. Dinosaurs drank me. Throughout millennia, I have flowed in rivers and drifted in clouds. I have meant good health to countless plants and animals, including human beings. Life on earth could not exist without me. My experiences are innumerable, but, recently, in a place called Darke County, Ohio, I had quite an adventure, which I should like to recount.

First, permit me to describe myself. Despite the simplicity of my form, I am complex. Only two atoms of hydrogen and one atom of oxygen make up all of me. Without meaning to sound boastful, I would say my personality is magnetic even electrifying! My oxygen atom's center, called the nucleus, carries eight positive electrical charges. Eight negatively-charged electrons rapidly orbit the center. They form four parts. Every pair sticks together because the two electrons are spinning in opposite directions on their own axis, generating a magnetic attraction. The four pairs repel one another and keep far apart.

My two hydrogen atoms are much smaller than my oxygen atom like two grapes next to a grapefruit (only on an atomically-tiny scale). The center of each hydrogen atom (called a proton) bears a positive charge. Opposites attract. Thus, two of the four negatively-charged electron pairs grab fast to the two positively-charged hydrogen centers. The angle between my hydrogen atoms is just about 104 degrees.

The hydrogen proton is tiny; it can come close enough to the ample numbers of electron pairs of other water molecules to create additional bonds. (For that matter, each of the two hydrogen atoms contributes an electron of its own.) You see, because my hydrogen atoms connect to my oxygen atom at an angle less than 180°, one side of me is slightly more positive, the other side is a tad more negative. My positive side attracts the negative parts of other water molecules. So two or three or more water molecules can string themselves together. Even as weak as these hydrogen bonds indeed are, they make water a liquid, instead of a vapor (or gas), at ordinary temperatures on earth.

In a barrel of water, the hydrogen bonds keep forming and breaking down so that not all of the molecules are attached to other water molecules at any one time. Generally speaking, the hotter it gets, the faster I and my fellow molecules move and the hydrogen bonds linking us molecules can break. Then I fly off by myself as vapor. I don't need a high temperature to do this, but higher heat speeds up the process.