context: Natural gas, or less often natural gas, is usually almost entirely methane (CH4), a significant fossil fuel for home heating and power generation. Natural gas has been created over time as biomass decomposes in the bedrock through the interaction of anaerobic bacterial activity and soil heat. In addition to methane, natural gas contains small amounts of ethane, propane, butane, pentane and other heavier hydrocarbons and sometimes nitrogen and helium. The natural gas CAS number is 8006-14-2. Natural gas is derived from natural gas and oil deposits and from shale, which is located in the earth's crust on land and at sea. Non-fossil methane produced from biomass of anaerobic bacteria is called biogas as distinct from natural gas [1].
question: What is natural gas used for?
answers.text: home heating and power generation