Mary Boll john, age 11, of Palo Alto, Calif., for her question:

Is water animal, vegetable or mineral?

Water, of course, is not an animal, nor is it a vegetable. But, when we think of a mineral we usually think of a stone or a lump of metal, something solid. Not all minerals are solids, however. Liquid mercury is a mineral. Could water also b e a mineral?

A mineral is a chemical or a compound of chemicals. So, of course, are plants and animals. The difference is this.  A mineral was made without the help of plants and animals. Bone and wood are not minerals, all the water in the world is created by nature. It is, then, a mineral.