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Science

How does fire work?

Fire is the result of combustion — a fast chemical reaction where a fuel combines with oxygen and releases heat and light. It needs three things at once: fuel, oxygen, and enough heat to start. Remove any one, and the fire goes out.

See it in motion.
Watch a 2-minute animated lesson that shows exactly how fire works.
▶ Watch the visual lesson

Step by step

  • 1Fire is a rapid chemical reaction called combustion.
  • 2It needs fuel, oxygen, and heat — the 'fire triangle'.
  • 3The reaction releases heat and light.
  • 4Removing fuel, oxygen, or heat extinguishes it.

Frequently asked questions

How does fire work?
Fuel reacts rapidly with oxygen when heated enough, releasing heat and light in a reaction called combustion.
What is the fire triangle?
The three things fire needs: fuel, oxygen, and heat. Remove any one and the fire dies.
Why does water put out fire?
It cools the fuel below its ignition temperature and blocks oxygen, breaking the fire triangle.

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