Combustion is a chemical process by which molecules combine with oxygen and are 'oxidized'. If you combust an organic molecule as much as possible, you will break it all the way down into water (H2
O) and carbon dioxide (CO2
). For example, if you had a molecule of methane (CH4
), mixed it up with some oxygen (O2
), and gave it a little bit of heat to get the reaction started, you would oxidize the methane into two water molecules and one carbon dioxide. The chemical equation would look like this:
O + CO2
I don't really know what you mean by 'combination', since this word doesn't really have any particular scientific meaning. However, the combination of oxygen with another molecule is a critical step in combustion.
(republished on 07/13/06)