Raja Ghosh, age 8, of Richmond, British Columbia, Canada, for his question:

WHAT IS FIRE?

Fire is heat and light that comes from burning substances.

In 1777, a French chemist named Antoine Lavoisier proved that burning is the result of rapid union of oxygen with other substances. As a substance burns, heat and light are produced.

Burning is also called combustion. Often oxygen unites with other substances at such a slow rate that little heat and no light are given off. When this happens, we call this process oxidation rather than burning or combustion.

Three conditions must exist before a fire can be made: there must be a fuel or a substance that will burn, the fuel must be heated to its kindling temperature and there must be plenty of oxygen.