John Bell Jr., age 13, of Kalispell, Mt., for his question:

HOW ARE CARBON DIOXIDE AND CARBON MONOXIDE DIFFERENT?

Carbon dioxide and carbon monoxide are both odorless, colorless and tasteless gases. But there the similarities stop. Carbon dioxide is produced as food oxidizes in human bodies and is then exhaled harmlessly. Carbon monoxide on the other hand, is an extremely poisonous gas.

Carbon monoxide results when fuels containing carbon such as coal or oil burn in stoves or furnaces that do not contain enough oxygen. Automboile engines also produce deadly amounts of carbon monoxide.

The chemical formula of carbon monoxide is CO. The gas molecule is made up of one atom of carbon and one atom of oxygen. Carbon dioxide's formula is Cot. This gas' molecules contain one atom of carbon and two of oxygen.

Human beings and animals inhale oxygen and exhale the carbon dioxide. Green plants take carbon dioxide from the air and give off oxygen when light shines on them. In the light, plants combine carbone dioxide with water to make food.

Carbon dioxide has many everyday uses. As an example, cakes rise in an oven because baking powder or yeast in the cake batter releases carbon dioxide. Carbon dioxide produces the fizz or sparkle in soft drinks, beer and sparkling wines.

Some fire extinguishes use carbon dioxide because it will not burn and it can put out fires. Carbon dioxide settles over a fire and shuts off the supply of oxygen in the air that a fire must have to burn. It does this because it is over one and half times as dense or heavy as air.

Back to carbon monoxide. Industry burns carbon monoxide to provide heat for manufacturing processes. The carbon monoxide is usually in a fuel gas such as water gas or producer gas. These gases are sometimes used to heat homes and to cook foods.

Carbon monoxide is also used to separate metals from their ores and to purify them.

Carbon monoxide can also be used to make other chemical compounds. Industry heats carbon from coal with either carbon dioxide, oxygen or water to make the carbon monoxide it used.

Carbon monoxide was first prepared in the laboratoy in 1776 by a French chemist named J.M.F. de Lassone. Its composition was identified in 1800 by an English chemist named William Cruikshank.

Now back again to carbon dioxide. The gas becomes a solid when cooled to minus 109.3 degrees Fahrenheit at atmospheric pressure. This solid is called dry ice because it will not melt to form a liquid as water does. Instead, it changes directly back to a gas. This process, in which a solid changes to a gas without first becoming a liquid, is called sublimation.

Carbon dioxide is also produced when wood, oil, gasoline or any fuel containing carbon burns with a large supply of oxygen. And posionous monoxide, we have learned, forms when carbon burns withou enough oxygen.