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NCERT Social Science Class 8 - Chapter 3: Mineral and Power Resources - Notes

CBSEClass 8Social Scienceखनिज और शक्ति संसाधन

Learning Objectives

  • Understand what minerals are and how they are classified
  • Learn about the distribution of minerals across the world and India
  • Differentiate between conventional and non-conventional sources of energy
  • Understand the need for conservation of minerals and power resources

Key Concepts

What are Minerals?

A mineral is a naturally occurring substance that has a definite chemical composition. Minerals are found in rocks, soils, and water. They are formed by natural geological processes over millions of years. Minerals are non-renewable resources.

Types of Minerals

Metallic Minerals: Contain metal in raw form. Divided into ferrous (containing iron, e.g., iron ore, manganese, chromite) and non-ferrous (not containing iron, e.g., gold, silver, copper, lead, bauxite, tin).

Non-Metallic Minerals: Do not contain metals. Examples: limestone, mica, gypsum, coal, petroleum.

Distribution of Minerals

Minerals are unevenly distributed across the world. Asia has large deposits of tin, manganese, and iron. Africa is rich in gold, diamonds, and copper. South America has iron, copper, and bauxite. Europe has iron ore and coal. North America and Australia also have significant mineral deposits.

In India: Iron ore is found in Jharkhand, Odisha, Chhattisgarh, and Karnataka. Bauxite is found in Jharkhand, Odisha, and Maharashtra. Mica deposits are in Jharkhand, Bihar, Andhra Pradesh, and Rajasthan.

Conventional Sources of Energy

Coal: Found in sedimentary rocks, formed from the remains of ancient vegetation. India has coal deposits in Jharia, Raniganj, Bokaro. Types: anthracite (highest quality), bituminous, lignite, peat.

Petroleum: Also called "black gold". Found between layers of rocks. Major producers: Saudi Arabia, Iran, Iraq, USA, Russia. In India: Mumbai High, Gujarat, Assam.

Natural Gas: Found with petroleum deposits. Used as domestic and industrial fuel. India has reserves in Jaisalmer, Krishna-Godavari delta, Tripura, and Mumbai offshore.

Hydroelectric Power: Generated by the force of falling water. It is a renewable source. Major dams: Bhakra Nangal (Sutlej), Hirakud (Mahanadi), Nagarjuna Sagar (Krishna).

Non-Conventional Sources of Energy

Solar Energy: Energy from the sun, harnessed using solar panels and solar cells. India receives abundant sunshine, making it suitable for solar power.

Wind Energy: Generated using wind turbines. India has wind farms in Tamil Nadu, Gujarat, Rajasthan, Maharashtra, and Karnataka.

Biogas: Produced from organic waste (plant and animal matter). Used for cooking and lighting in rural areas.

Tidal Energy: Harnessed from the rise and fall of ocean tides. India has potential sites in the Gulf of Kutch and Gulf of Khambhat.

Geothermal Energy: Heat energy from the Earth's interior. Used in countries like USA, Iceland, New Zealand. India has potential in Puga Valley (Ladakh) and Manikaran (Himachal Pradesh).

Nuclear Energy: Obtained by splitting atoms of uranium and thorium. Nuclear power stations in India: Tarapur (Maharashtra), Rawatbhata (Rajasthan), Kalpakkam (Tamil Nadu), Narora (Uttar Pradesh), Kakrapar (Gujarat), Kaiga (Karnataka).

Summary

Minerals are naturally occurring non-renewable substances classified as metallic and non-metallic. They are unevenly distributed across the world. Conventional energy sources like coal, petroleum, and natural gas are finite and polluting. Non-conventional sources like solar, wind, tidal, and geothermal energy are cleaner and renewable. Conservation of both minerals and energy resources is essential for sustainable development.

Important Terms

Mineral
A naturally occurring substance with a definite chemical composition
Ore
Rocks from which minerals are mined profitably
Ferrous Minerals
Metallic minerals containing iron (e.g., iron ore, manganese)
Non-Ferrous Minerals
Metallic minerals not containing iron (e.g., copper, gold, bauxite)
Fossil Fuels
Fuels formed from the remains of ancient organisms (coal, petroleum, natural gas)
Geothermal Energy
Heat energy obtained from the Earth's interior
Nuclear Energy
Energy obtained by splitting atoms of radioactive elements

Quick Revision

  1. Minerals are non-renewable and unevenly distributed on Earth
  2. Metallic = ferrous (with iron) + non-ferrous (without iron)
  3. Coal types by quality: anthracite > bituminous > lignite > peat
  4. Petroleum is called "black gold"
  5. Non-conventional sources: solar, wind, biogas, tidal, geothermal, nuclear
  6. India's nuclear power stations: Tarapur, Rawatbhata, Kalpakkam, Narora, Kakrapar, Kaiga

Practice Tips

  • Mark the locations of major mineral deposits and power stations on a map of India
  • Compare conventional vs. non-conventional energy sources in a table
  • Remember the classification hierarchy: minerals → metallic/non-metallic → ferrous/non-ferrous
NCERT Social Science Class 8 - Chapter 3: Mineral and Power Resources - Notes | EduMunch