Why are coal petroleum and natural gas called fossil fuels?

More Questions

• Why coal and petroleum are called fossil fuels?
• Why is natural gas called a clean fuel?
• Why is natural gas is called a clean fuel?
• Why are fossil fuels exhaustible natural resources?
• Why fossil fuels are exhaustible natural resources?
• What is the study of fossils called?
• What is the definition of natural gas?
• Why should we use fossil fuels judiciously?
• Why should we conserve fossil fuels?
• What is the main constituent of natural gas?