Energy Resources Are natural resources that humans use to produce energy. The energy resources on which humans depend on the most are fossil fuels. Fossil fuels are nonrenewable energy resources that form in the Earths crust over millions of years from the buried remains of once living organisms. Energy is released from fossil fuels when they are burned Liquid Fossil Fuels: Petroleum Gaseous Fossil Fuels: Natural Gas Solid Fossil Fuels: Coal Petroleum or crude oil, is an only mixture of flammable organic compounds from which liquid fossil fuels and other products are separated. Petroleum is separated into several types of fossil fuels and products in refiniries, among the types of fossil fuels separated from petroleum are: gasoline, jet fuel, kerosene, diesel fuel, and fuel oil. Fossil fuels refinery Most natural gas is used for heating or generating electricity. The stove that you use at home may be powered by gas. Methane is the main component of natural gas. But other natural gas components such as butane and propane can be separated and used. Coal is a solid fossil fuel formed underground from buried, descomposed plant material. Coal, was once the leading source of energy in the United States. People burned coal for heating and transportation. People began to use coal less because of the amount of air pollution and because better energy resources were discovered. Now Coal is used to produce electricity. How do Fossil Fuels form? Different types of fossil fuels form in different ways and from different types of organisms. Petroleum and natural gas form mainly from the remains of microscopic sea life. Their remains form sediment in the ocean floor, through physical and chemical changes over millions of years, the remains become petroleum and gas. Permable rocks become reservoirs of petroleum and natural gas, this is an ongoing process. Coal forms differently, it forms underground over millions of years ago from decayed swamp plants. When swamp plants die, they sink to the bottom, this begins the formation of coal. Homework Investigate and write in your notebook, the advantages and disadvantages of the use of fossil fuels, describe each one.