Introduction

"Burning" redirects here. For combustion without external ignition, see spontaneous combustion. For the vehicle engine, see internal combustion engine. For other uses, see Burning (disambiguation) andCombustion (disambiguation).

The flames caused as a result of afuel undergoing combustion (burning)

Combustion /kəmˈbʌs.tʃən/ orburning^[1] is a high-temperatureexothermic chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed smoke. Combustion in a fire produces a flame, and the heatproduced can make combustion self-sustaining. Combustion is often a complicated sequence of elementaryradical reactions. Solid fuels, such as wood, first undergo endothermicpyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce them. Combustion is often hot enough thatlight in the form of either glowing or aflame is produced. A simple example can be seen in the combustion ofhydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. This reaction releases −242 kJ/mol of enthalpy (heat):