The chemical element needed for fire is oxygen. Fire is a chemical reaction known as combustion, which requires three essential components to ignite and sustain: fuel, heat, and oxygen. When oxygen is present, it reacts with the fuel (such as wood, paper, or gasoline) at a sufficient temperature, producing heat and light in the form of flames. The process releases gases, including carbon dioxide and water vapor. In environments lacking oxygen, fire cannot burn, which is why methods like smothering a fire or using fire extinguishers often involve reducing oxygen levels to extinguish flames.