Summary:
- Coal forms from dead plants that settled at the bottom of swamps millions of years ago.
- Coal is mostly carbon, but some other elements can be found in coal, including sulfur.
- The coal with the least sulfur is the cleanest coal.
- The heat from the burning coal is used to boil water, which makes steam.
- The steam spins turbines, which creates electricity.
- The United States is rich in coal (Figure below).
- Many regions of the country have significant coal deposits.
- The hardest type of coal, anthracite, is a metamorphic rock.