What is a chemical equation for the combustion of hydrogen?

The chemical equation for the combustion of hydrogen is 2H₂ + O₂ → 2H₂O. During hydrogen combustion, the heat from burning makes hydrogen chemically react with oxygen gas, O₂, in the air to form water.

In this reaction, two molecules of hydrogen gas, H₂, react with one molecule of O₂ to form two molecules of water, H₂O. A significant amount of energy, in the form of heat, is required to start the reaction. Due to the presence of extreme heat, the water created by the reaction is not a liquid but is gaseous water vapor. The reaction also generates large amounts of heat, which is produced by the breaking of the chemical bonds connecting the gases.