carbon mostly and hyrogen
carbon
Fossil fuels are the remains of decomposition of buried dead organisms under pressure. The common fossil fuels are oil , gas and coal.
Fossil fuels are rare now as there are not many left but people think they are common because they are used everywhere.
carbon
Carbon is the element of the life and fossil fuels.
The most common fossil fuels are coal, oil and natural gas.
Sulfur is the element present in impurities in fossil fuels that can produce sulfur dioxide when the fuel burns.
Oxygen is required for the combustion of fossil fuels. During combustion, the carbon and hydrogen in the fossil fuels react with oxygen to produce carbon dioxide, water, and heat energy.
Carbon dioxide (CO2) is a gas produced by burning fossil fuels that contains the element carbon. It is a greenhouse gas that contributes to climate change.
Both are fossil fuels.
When fossil fuels are burned, some of the chemical energy stored in them is converted into thermal energy.
Fossil fuels are mostly made up of carbon, along with varying amounts of hydrogen, sulfur, and other elements.