Coal and Petroleum of Class 8


Fuel is any material that is burned to obtain energy that can be used to heat or move another object. Fuel releases energy through a chemical reaction known as combustion. 

Properties of a good fuel:

  • Should be readily available.
  • Should be cheap.
  • Should burn easily at a moderate rate.
  • Should produce a large amount of heat.
  • Should not leave behind any undesirable substances.

Wood was the first fuel that was used 2 million years ago by homo erectus, the predecessor of human beings.

Incomplete combustion of carbon fuels causes the release of carbon monoxide – a very harmful gas.

Combustion of fuels causes the release of carbon dioxide, which leads to global warming. Such rise in temperatures can cause melting of polar glaciers, a rise in sea level, and the flooding of low-lying areas of the world.

Oxides of sulphur and nitrogen dissolve in rain water to form acid rain, which ruins soil, crops and buildings. By choosing the right fuel, we can reduce the negative impact on the environment. A great example of this is cars, buses and auto rickshaws that run on Compressed Natural Gas, or CNG, instead of petrol. CNG is a much cleaner and cheaper fuel.To score More in your class 8 refer NCERT solutions for class 8 .

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