You have seen candles burning. An orange flame dances around the wick, while the wax melts underneath and drips down. The candle gets shorter as the wax melts.
The candle wax has a kind of stored-up energy. It is a fuel. A fuel is something that is burned to make light, heat, or a push that makes things move. The coal, oil, and gas used to heat homes and other buildings and to cook food are fuels. The petrol in a car and the wood in a fireplace are fuels, too.
The same thing happens to every kind of fuel when it burns. When it starts burning, the heat makes it break down and change to other things, such as ashes. As the fuel breaks down, it gives off energy. Some of the energy is light, and some is heat.
When petrol is burned in a car engine, the heat energy makes the engine push. The push from the engine makes the car run.
The energy stored in a fuel is called chemical energy.
Picture Credit : Google