Coal
Definition
Example
"Coal burns very hot."
"The factory used coal to run its machines before switching to clean solar energy."
"Old steamships needed large amounts of coal put into their engines to keep moving forward."
Explanation
Coal is a black or brown rock that comes from plants buried underground millions of years ago. Over time, heat and pressure changed those plants into coal. It burns easily and produces heat, so people have used it for cooking, heating, and running machines. For example, old trains used coal to make steam that moved the wheels. Coal is still used today in power plants to make electricity, though it can pollute the air. Imagine coal like a natural “battery” created long ago, storing energy from ancient plants that we can release when we burn it.