Dale Finneyp, age 9, of El Cajon, Calif., for his question:

What is the formula for wood?

The basic ingredient in wood is cellulose. And ouch molecule of cellulose is composed of 21 atoms ‑ six of carbon, ten of hydrogen. and five of oxygen. The chemical formula, then, is C6H1005. However., this is the formula only for cellulose and not the entire recipe for making wood. Each type of tree uses its own wood recipe, slightly different from its neighbors.

Most wood contains 60 per cent cellulose. About 28 per cent of wood is lignin, a strong cement used to band the molecules in sturdy cell walls. The rest of the recipe is composed of resins, minerals and sugars.

The basic ingredients of wood are common chemical elements. Yet only a plant can put them together to make a tree trunk.