Nuclear energy and coal
What, am I helping you with your homework? I thought school was out for the summer in North America!
According to the US Nuclear Regulatory Commission, uranium is used for fuel in nuclear power plants. If you go to the Students' Corner of their website, you will learn that nuclear energy is a way of creating heat through the fission process of atoms. All power plants convert heat into electricity using steam. At nuclear power plants, the heat to make the steam is created when atoms split apart -- called fission. The fission process takes place when the nucleus of a heavy atom, like uranium or plutonium, is split in two when struck by a neutron. The "fissioning" of the nucleus releases two or three new neutrons. You might also enjoy looking at the California Energy Commission website that presents The Energy Story. Chapter 13 looks at nuclear energy.
The short answer on coal is "millions of years." According to the online Coal Research Tutorial from the Argonne National Laboratory, there were several periods in ancient history where land and climate conditions were just right to allow vast swamps to form and convert to coal over very long periods. One was during the Carboniferous around 300 million years ago. The second was in the Mesozoic, particularly in the Cretaceous and Jurassic periods. In North America, coal was formed in both eras. The coals in the Midwest and Eastern US were formed during the Carboniferous, while the coals in the Western United States were formed in the Mesozoic.
