High School Earth, Space, and Geophysical Curriculum Essentials May 2009 9. Boulder Valley School District High School Earth, Space, and Geophysical. Science Curriculum Essentials Document. Enduring Understandings. are the big ideas central to a content area that have lasting value beyond the classroom and.
See also: Coal gasification and Coal seam gas. Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system. Town gas is a more general term referring to manufactured gaseous fuels produced for sale to consumers and municipalities.
Coal is a nonrenewable energy source because it takes millions of years to create. It is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbonsâmolecules containing hydrogen and carbon. The energy in coal comes from the remains of prehistoric plants and animals, making it part of the fossil fuels family.