Answer:
Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
Explanation:
When plants die, they are no longer in contact with the air. The pressure of rocks and the earth makes the plant matter undergo a chemical change witch transforms the plant matter into coal. The process takes millions of years. This is one of the reason why coal is a non-renewable natural resource.
