It sure is great to be free again. Free to roam the atmosphere that is. I'm hanging out in a methane molecule now. Being a gas sure is fun...constant random motion and the like. I wish I could stay this way forever.
Fossil fuels are a broad name given to a variety of fuels found in the earth. These fuels have the name fossil fuels because they probably formed from the remains of ancient decaying organisms. As these organisms died, they were covered with dirt, rocks, and other sediment. Over many years the pressure caused the organic compounds to convert into fossil fuel which is now recovered as crude oil, coal or natural gas.
Most fossil fuels are hydrocarbons such as methane or natural gas. These fuels are used in a variety of applications. Gasoline or rather its prime component octane powers hundreds of machines. Propane is commonly used in gas grills for cooking. Acetylene provides the intense heat used by welders. Fossil fuels provide all this energy in their chemical bonds between hydrogen and carbon atoms. This energy is usually released in a combustion process.