Combustion or 'burning' is a chemical reaction between usually a hydrocarbon and oxygen.  It is a type of exothermic reaction which releases CO2, heat/light and water vapour.


The chemical equation of methane reacting with oxygen to produce  carbon dioxide and water + heat/light

Complete oxidation in the atmosphere is not possible and there are a number of other chemicals produced, especially nitrogen oxide compounds NOx

Combustion is a key element of natural disasters or hazards such as bush fires, household or industrial fires.


A bonfire demonstrates a complex type of combustion. image: R.Conan-Davies