Cheryyl Myers, age 11, of Woodlake. Calif., for her question:

Why is some water hard and some soft?

Fresh water is eager to team up with soap and create a frothy mass of soft filmy bubbles and lather. The softest water is fresh rain, trapped in a pail as it falls from the clouds. But in nature, the fallen rain gathers in running rivers and much of it sinks through the soil and dawn through the gritty rocks below the surface.

These rocks are made of minerals, and some minerals are always eager to dissolve in water. The rain water in the ground laps at these minerals with thirsty tongues, disso1ves them and carries them away. Other mineral chemicals are disso1ved by rivers and lakes. It is hard to make lather or wash the laundry with this mineral bearing water. Our reservoirs give us hard water when they gather the rainfall that has seeped through limestone or other rocks in which the chemicals are easy to dissolve.