Gene McTeer, age 11, of San Bernardino, California, for his question:

What are organic chemicals?

Modern chemistry identifies about 525,000 chemical compounds and classifies them in two groups. About 500,000 of them are organic compounds, the rest are inorganic compounds. A compound is made of molecules, all of the same kind. A molecule, of course, is a package of assorted atoms, though the atoms in some molecules are all of the same kind. The word organic is associated with life and organic substances are associated with present ox past animal or plant life. They may be heaps of manure or piles of decaying leaves, coal from ancient forests or petroleum from the remains of ancient sea creatures.

All the organic chemicals have one item in common. Their molecules are sure to contain an atom of carbon. The molecules of inorganic chemicals have no carbon atoms. Almost all  inorganic compounds also contain hydrogen and most of them contain oxygen. Others may contain phosphorus or sulphur or one or more of the halogen chemicals. Many organic . compounds are very complex and their large molecules contain all these and still other atoms. But every organic molecule has at least one atom of carbon.