Kay Quesenberry, age 11, of Oak Hill, W, Va., or her question:

What makes water hard or soft?

The most important item to every community is a plentiful supply of clean, fresh air. Second to this is a plentiful supply of clean, fresh water. This water, of course, comes from rain and rainwater, and as a rule it is the purest water found in nature. Over factories and large built up areas, however, the falling raindrops may gather up particles of soot, smog and carbon dioxide.

If these were all the impurities, our water works could sift them with ease. All the water would be soft water, willing and eager to make bubbles with the soap. But sad to say,  we cannot gather rainwater as it falls  at least not enough to supply all our needs. We must wait for it to fall onto and into the ground and then gather into streams and lakes.

Water, of course, is a great solvent, or dissolves. They say that the constant dripping of water will wear away the hardest stone. And this is true. But what happens to the stone that is worn away? It is broken up into particles too small for our eyes to see and these particles are dissolved, or suspended, in the water.

Hour by hour, the greedy little tongues of running water lap at the stones, the rocks and the soil. This water flows down hills and slopes and countless streams and springs gather to form lakes and rivers. On the way it gathers dissolved chemicals. Water which flows down into the hills to form underground streams and springs usually gathers more chemicals. Our reservoirs are drawn from large bodies of water which have traveled through many rocky adventures.

Same of the minerals brushed by the running water dissolve more easily than others. Ono of the soft minerals is limestone.

If your water supply flows through a region of limestone, it is sure to contain a lot of the chemical calcium carbonate. Calcium carbonate, sand and magnesium salts are the chief hard water culprits. When dissolved in water, they fight the soap. They refuse to foam and bubble. They do not get you or the laundry clean and what's more, they tend to leave a scummy ring around the bath tub. They also leave limey crusts in kettles and water pipes.

Wherever you lives your water supply has a slight taste from the chemicals it gathers on the way to the reservoir. If you move to another town, you may notice a different taste in the water for this reason. At the reservoir, the water goes through many processes to remove debris, decaying materials and harmful bacteria. But few if any reservoirs remove the chemicals which make water hard.

Some homes use a water softening machine. The hard water chemicals are removed before the water reaches the faucets. Some people rely on soda o r other water softening chemicals. These chemicals combine with the hard water chemicals and sift them down to the bottom. The water is then almost as soft as new fallen rain and almost as willing to make bubbles.