1. What is a Combustion Reaction?

A combustion reaction is a chemical reaction in which a substance reacts with oxygen and releases energy (usually as heat and light).

• A fuel (something that burns)
• Oxygen (from the air)

2. Key Features of Combustion

• Need oxygen
• Produce energy (heat and/or light)
• Form new substances (products)

3. Common Fuels That Burn

4. Products of Combustion

5. Exothermic Reactions

• Combustion reactions are exothermic.
• They release energy to the surroundings.
• A candle gives out heat and light.

6. The Fire Triangle

• Fuel
• Oxygen
• Heat

If any one is removed, the fire goes out.

7. Complete and Incomplete Combustion

8. Real-Life Examples

• Candle → Wax → CO₂ + H₂O
• Car → Petrol → CO₂ + H₂O
• Gas stove → Methane → CO₂ + H₂O
• Campfire → Wood → CO₂ + H₂O + ash

9. Writing Word & Symbol Equations

✏️ Worked Examples

• Magnesium + Oxygen → Magnesium oxide
• Propane + Oxygen → Carbon dioxide + Water

🧠 Practice Questions

1. What is combustion?
2. Name two things needed for combustion.
3. Is combustion exothermic or endothermic?
4. Write word equations for burning hydrogen, ethanol, magnesium.
5. Is a yellow smoky flame complete or incomplete combustion?
6. Name the three parts of the fire triangle.
7. What happens if oxygen is removed?
8. Write word equations for burning iron and butane.