Fossil Fuels
Coal and petroleum were formed from fossilized plants and animals and hence they are called fossil fuels.
These notes are based on the chapter sources of energy from class 10 science NCERT book and CBSE syllabus.
Coal
- Coal was formed from plants millions of years ago.
- Such plants were present around swamps.
- The plants got buried under swamps millions of years ago.
- In due course of time, those plants were converted into coal due to high pressure and high temperature inside the earth. This process is called carbonization.
During the days of steam engine, coal was used in steam engines. Moreover, coal was also used as kitchen fuel, before LPG became popular.
Now-a-days, coal is mainly being used in the industries and in thermal power plants. Coal may not be visible in our everyday life but coal is the largest source of energy for us.
Petroleum
- Petroleum was also formed millions of years ago.
- Plants and animals got buried under the ocean surface millions of years ago.
- They were converted into petroleum, in due course of time because of intense heat and pressure inside the earth.
Petroleum is the third major source of energy being used today. Petroleum products are used as automobile fuel and also in the industries. Natural gas mainly comes from oil wells and is also a major source of energy.
Advantages of Fossil Fuels
- Fossil fuels are easily available.
- Humans have perfected the technologies to harness fossil fuels.
- Most of the engines and other applications run on fossil fuels.
Harms of Fossil Fuels
Burning of fossil fuels produces harmful gases such as carbon dioxide, carbon monoxide and oxides of sulfur and nitrogen. These gases cause air pollution. Carbon dioxide causes global warming.
- Fossil fuel is non-renewable and exhaustible source of energy.
- Fossil fuels are not environment-friendly.
- Extraction of coal damages flora and fauna at a place.
- Coal mining produces too much dust.
- Combustion of fossil fuels causes environmental pollution.