Why does fire need oxygen?
Show answer & explanation
Answer: Oxygen enables combustion
Oxygen enables combustion ✓ — Correct! Fire is a rapid oxidation reaction. Fuel molecules react with oxygen, breaking chemical bonds and forming new ones (like CO2 and H2O), releasing energy as heat and light. Without oxygen, this reaction can't occur. That's why smothering a fire with a blanket works - you cut off the oxygen supply!
It makes flames visible — Wrong. Flames are visible because of glowing hot particles and excited molecules, not because of oxygen. Flames can actually occur in different colors depending on what's burning and at what temperature, but oxygen is needed for the chemical reaction, not visibility.
It provides fuel — Wrong. Oxygen is not the fuel - it's the oxidizer. The fuel is what burns (wood, gasoline, etc.). Oxygen reacts with the fuel in a chemical reaction. Fire needs three things: fuel, oxygen, and heat (the fire triangle).