Blake ZicGrath, age 16, of Highland Parks New Jersey, for his question:

What is the ozone layer?

Ozone is an active form of oxygen with a tangy odor. It makes up about one part of every million parts of the air we breathe. Higher up, the quota in the atmosphere increases. The so called ozone layer is about 15 miles above the earth. Here the air may contain six or more parts of ozone per million parts. This is where the active properties of ozone sift out ultraviolet energy from the sun. In large doses, this form of solar radiation is destructive to living cells in both plants and animals. The upper ozone layer acts as a shield to protect all life on earth.

The relation of ozone to oxygen is very simple. Ordinary oxygen is a molecule of twin oxygen atoms. The ozone molecule is a set of triplets, with a third oxygen atom loosely attached to the twins. Energy is required to add the extra atom. Particles of oxygen in the air are converted to ozone by electric storms and around electrical equipment. High above the earth, oxygen molecules use solar energy to form ozone    and create the earth's protective ozone layer.