what is coal? how it is obtained from the earthcrust
Answers
Coal is a black or brownish-black sedimentary rock that can be burned for fuel and used to generate electricity. It is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning).
Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.
Fossil fuels are formed from the remains of ancient organisms. Because coal takes millions of years to develop and there is a limited amount of it, it is a non renewable resource.
We obtain coal from underground seams. A seam is a layer of ore or coal that is thick enough to be profitably mined. We obtain the coal in one of two ways: By surface mining, which involves removing the soil and rock above the coal seam so that it can be removed from the surface