Source: VIII NCERT Science Chapter 5
Based on the availability the natural resources can be broadly classified into two groups:
1. Inexhaustible Natural resources - These are present in unlimited quantity and cannot be exhausted by human activity. Eg: Sunlight, air.
2. Exhaustible Natural resources - These are present in limited quantities and can be exhausted by human activity. Eg: Minerals, coal, petroleum, forests, natural gas etc.
- Coal, petroleum and natural gas are known as fossil fuels as they were formed from the fossils.
- About 300 million years ago the earth has dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. As coal contains mainly Carbon, the slow process of conversion of dead vegetation into coal is called Carbonisation.
- Coal, when heated in air, burns and produces mainly carbon dioxide gas.
- Coal is processed in industry to get some useful products such as Coke, Coal, tar and Coal gas.
- Coke:
It is tough, porous and black substance.
It is almost pure form of Carbon.
It is used in the manufacture of steel and in extraction of many metals.
- Coal Tar:
It is a black,thick liquid with unpleasant smell.
Products obtained from coal tar are used in the manufacture of synthetic dyes, drugs, explosives, perfumes, plastics, paints, roofing materials, photographic materials.
Naphthalene balls used to repel moths and other insects are also obtained from coal tar.
- Coal Gas;
It is obtained during the processing of coal to coke.
It is used for street lighting in London for the first time.
- Petrol and diesel are obtained from a natural resource called Petroleum.
-Petroleum is formed from the organisms living in the sea.As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years, absence of air, high temperature and high pressure transformed the dead organisms into petroleum and natural gas.
- Petroleum is a dark oily liquid. It is a mixture of various constituents such as petroleum gas, petrol, diesel, lubricating oil, paraffin was etc.
- The process of separating the various constituents/fractions of petroleum is known as refining.
- The world's first oil well was drilled in Pennyslvania, USA in 1859.
- Bitumen is a petroleum constituent used in paints and road surfacing.
- Natural Gas is stored under high pressure as compressed natural gas (CNG).
- CNG is used for power generation.
- CNG is a cleaner fuel.
- Hydrogen gas obtained from natural gas is used in the production of fertilisers(urea).
- Petroleum is also called as Black Gold.
Based on the availability the natural resources can be broadly classified into two groups:
1. Inexhaustible Natural resources - These are present in unlimited quantity and cannot be exhausted by human activity. Eg: Sunlight, air.
2. Exhaustible Natural resources - These are present in limited quantities and can be exhausted by human activity. Eg: Minerals, coal, petroleum, forests, natural gas etc.
- Coal, petroleum and natural gas are known as fossil fuels as they were formed from the fossils.
- About 300 million years ago the earth has dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. As coal contains mainly Carbon, the slow process of conversion of dead vegetation into coal is called Carbonisation.
- Coal, when heated in air, burns and produces mainly carbon dioxide gas.
- Coal is processed in industry to get some useful products such as Coke, Coal, tar and Coal gas.
- Coke:
It is tough, porous and black substance.
It is almost pure form of Carbon.
It is used in the manufacture of steel and in extraction of many metals.
- Coal Tar:
It is a black,thick liquid with unpleasant smell.
Products obtained from coal tar are used in the manufacture of synthetic dyes, drugs, explosives, perfumes, plastics, paints, roofing materials, photographic materials.
Naphthalene balls used to repel moths and other insects are also obtained from coal tar.
- Coal Gas;
It is obtained during the processing of coal to coke.
It is used for street lighting in London for the first time.
- Petrol and diesel are obtained from a natural resource called Petroleum.
-Petroleum is formed from the organisms living in the sea.As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years, absence of air, high temperature and high pressure transformed the dead organisms into petroleum and natural gas.
- Petroleum is a dark oily liquid. It is a mixture of various constituents such as petroleum gas, petrol, diesel, lubricating oil, paraffin was etc.
- The process of separating the various constituents/fractions of petroleum is known as refining.
- The world's first oil well was drilled in Pennyslvania, USA in 1859.
- Bitumen is a petroleum constituent used in paints and road surfacing.
- Natural Gas is stored under high pressure as compressed natural gas (CNG).
- CNG is used for power generation.
- CNG is a cleaner fuel.
- Hydrogen gas obtained from natural gas is used in the production of fertilisers(urea).
- Petroleum is also called as Black Gold.