What is combustion?

Combustion and conservation of mass: fuel + O₂ → CO₂ + H₂O + heat. When something burns, it joins with oxygen from the air and its atoms regroup into new substances, mostly carbon dioxide and water, releasing heat. A fuel made of carbon and hydrogen joins with oxygen.

Read how it works: What is combustion? · The history of combustion and conservation of mass · More boxes on Glassbox

Chapters in this interactive model

1. Burning makes nothing vanish: Burn gas, petrol or wood in a sealed jar on a balance. Count the atoms, then weigh them.
2. A gas cylinder makes three times its weight in CO₂: The LPG hob and its chimney, and steel wool that gets heavier as it burns.
3. A litre of petrol makes 2.3 kg of CO₂: Inside a petrol engine: the 14.7 : 1 mixture, lean and rich, and the catalytic converter.
4. Put out a fire, and breathe out your lunch: The fire triangle and how extinguishers break it, and why lost fat leaves through your lungs.
5. Vanishing candles, E = mc², and a silent killer: Where mass only seems to go, where a tiny bit really does, and why incomplete burning kills.