Combustion & Energy

What is Combustion?

Combustion is a chemical reaction that releases energy through heat and light. 

• Combustion is a chemical reaction between a fuel (such as wood, gas, or oil) and oxygen from the air.
• This reaction is exothermic, releasing energy (primarily as heat and sometimes light).
• Carbon dioxide (CO₂) and water vapor (H₂O) are common combustion products.
• To begin, the process needs to reach a temperature called the ignition point. Once started, the reaction sustains itself as long as fuel and oxygen are available.

Combustion & Energy Use

Combustion is how we unlock stored chemical energy and turn it into useful forms like motion, heat, and electricity. 

• In car engines, gasoline combusts inside cylinders, pushing pistons and converting chemical energy into kinetic (movement) energy.
• Power plants use combustion to heat water into steam, which spins turbines and generates electrical energy.
• Thermal energy from combustion is used for heating buildings, cooking food, and industrial processes like metalworking.
• Combustion in jet engines and rockets is designed to happen in controlled bursts, producing thrust to overcome gravity.

Fun Facts

Here are some interesting facts about combustion & energy:

• Fire needs three things to burn: fuel, oxygen, and heat — the fire triangle.
• Candle flames have layers where the blue part is the hottest!
• Space rockets use a controlled combustion reaction to launch into orbit.
• Combustion is used in fireworks to make color: copper = blue, strontium = red!

Review

Let’s quickly recap what we learned about combustion & energy:

• What gas is needed for combustion? Oxygen
• What kind of change is combustion? Chemical
• What form of energy is released during combustion? Heat
• What harmful gas can be produced by combustion? Carbon Dioxide