Fossil fuels

Examples of fossil fuels

Coal

Oil

Gas

How long does it take fossil fuels to form

They are former over millions of years

Some of the carbon from photosynthesis ends up in fossil fuels

How would you describe fossil fuels

Non renewable. If we keep using them then they will run out

How is coal formed

From the remains of ferns and trees. If these die in marshy wetlands then they do not decompose, that can be due to a lack of oxygen or acidic conditions as they prevent bacteria from carrying out decomposition. Over time, the plant remains are covered with sediment and compressed. High temperature and pressure creates coal

How is crude oil formed

From plankton which are tiny plants and animals found in the sea. When they die, they settle in mud on the sea bed. If oxygen is not present then they do not decompose. Over time they are compressed by sediment. Heat and pressure then convert them into crude oil

Natural gas

Natural gas is mainly the hydrocarbon methane. We often find natural gas near deposits of oil and natural gas is formed from plankton in a similar way to oil.

What is the key fact

All fossil fuels contain trapped carbon. That carbon was part of the carbon dioxide taken in by photosynthesis