A combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams.
Coal is also used in manufacturing. If coal is heated the gases, tars and residues produced can be used in a number of manufacturing processes. Plastics, roofing, linoleum, synthetic rubber, insecticides, paint products, medicines, solvents and synthetic fibers all include some coal-derived compounds. Coal is the world s most plentiful fossil fuel. It is formed from the remains of land-based plants buried hundreds of millions of years ago and subjected to long periods of heat and pressure. The four types of coal are peat, lignite, bituminous, and anthracite. Peat is often not listed as a type of coal since the use of it as an energy source is limited today. However, it's still a type of coal and can be used as an energy source. Peat is the first step in coal formation. Coal is a fossil fuel created from the remains of plants that lived and died about 100 to 400 million years ago when parts of the earth were covered with huge swampy forests. Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. Coal is made of the remains of ancient trees and plants that grew in great swampy jungles in warm, moist climates hundreds of millions of years ago. Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. In 1999, world gross carbon dioxide emissions from coal usage were 8,666 million tonnes of carbon dioxide. Coal is a combustible sedimentary rock composed mostly of carbon and hydrocarbons. It is the most abundant fossil fuel produced in the United States, but it is a nonrenewable resource. The energy in coal comes from the energy stored by plants that lived hundreds of millions of years ago in swampy forests. Coal is a combustible rock and along with oil and natural gas it is one of the three most important fossil fuels. Coal has a wide range of uses; the most important use is for the generation of electricity. Coal forms from the accumulation of plant debris, usually in a swamp environment. When plant debris dies and falls into the swamp the standing water of the swamp protects it from decay. Swamp waters are usually deficient in oxygen, which would react with the plant debris and cause it to decay. Coal (from the Old English term col, which has meant mineral of fossilized carbon since the 13th century) is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams.
http://geology.com/rocks/coal.shtml http://www.energy.alberta.ca/coal/645.asp http://study.com/academy/lesson/what-is-coal-facts-types-formation-uses.html http://lsa.colorado.edu/essence/texts/coal.html http://www.eschooltoday.com/energy/non-renewable-energy/what-is-coal.html https://en.wikipedia.org/wiki/Coal http://teeic.indianaffairs.gov/er/coal/restech/uses/index.htm http://geology.com/rocks/coal.shtml https://en.wikipedia.org/wiki/Coal
what is coal