According to the European Chemistry Thematic Network, wood reacts with oxygen when it burns. The combustion of wood produces carbon dioxide and water, which are reaction products released as gases into the atmosphere.
The European Chemistry Thematic Network explains that solid wood disappears when it burns, and it is converted into gas products, eventually leaving only ashes that consist of wood’s minor components that remain solid and do not burn. The production of heat and light is another primary effect of combustion.
The European Chemistry Thematic Network expounds that in wood combustion, a chemical reaction occurs. This means some molecules are destroyed while new ones are formed. When wood burns, oxygen and sugar molecules disappear, and they are replaced by carbon dioxide and water molecules. Molecules are not conserved in chemical reactions. However, the same atoms that make up the reactant molecules form the product molecules. Thus, atoms are rearranged in different molecules.
Tom Harris explains at Howstuffworks that fire is produced from a chemical reaction between wood and oxygen. The combustion reaction occurs when the fuel, in this case the wood, is heated to its ignition temperature. The wood can be heated to a high temperature by various things, including a match, friction, lightning and focused light. When the wood reaches around 150 degrees Celsius, the heat decomposes the wood’s cellulose material and releases volatile gases known as smoke.