Fossil fuels

• how long does it take for fossil fuels to form?

  Millions of years
• Are fossil fuels non-renewable or renewable?

  Non-renewable, this means they will run out if we keep using them
• How is coal formed?

  Coal is formed from the remains of ferns and trees, if these die in marshy wetlands then they do not decompose which could be due to a lack of oxygen or acidic conditions. These both prevent bacteria from carrying out decomposition. Over time, the plant remains covered with sediment and compressed, high temperatures and pressure creates coal.
• How is crude oil formed?

  Formed from plankton which are tiny plants and animals found in the sea, when these die they settle in mud on the seabed. If oxygen is not present then they do not decompose. Overtime, they are compressed by sediment and heat and pressure then covert them into crude oil.
• What do all fossil fuels contain?

  Trapped carbon which was part of the carbon dioxide taken in by photosynthesis.
• How is natural gas formed?

  Natural gas is mainly the hydrocarbon methane, we find natural gas near deposits of oil this is because natural gas is formed from plankton in a similar way to oil.