UP board Class 8: Science - Chapter : MINERALS AND POWER RESOURCES

1. Minerals:

Minerals are naturally occurring substances that are found in the earth’s crust. They have a definite chemical composition and physical properties.

Types of Minerals:

Metallic Minerals: Minerals from which metals can be extracted (e.g., iron, gold, silver, copper).

Non-Metallic Minerals: Minerals that do not contain metals (e.g., coal, salt, mica, limestone).

2.Extraction of Minerals:

Mining: The process of extracting minerals from the earth.

• Open-pit mining: Extracting minerals by digging at the surface.
• Shaft (Underground) mining: Digging tunnels and shafts to extract minerals deep beneath the surface.

3. Power Sources:

Conventional Sources of Energy:

 Those sources which we are using from very long time.

• Coal: The most abundant fossil fuel used for generating electricity and as fuel in industries.
• Petroleum: A liquid fossil fuel used for transportation and manufacturing petrochemicals.
• Natural Gas: A cleaner fossil fuel used for heating, cooking, and electricity generation.
• Hydro Power: Energy produced from the flow of water in dams.

Non-Conventional Sources of Energy:

• Solar Energy: Energy from the sun used in solar panels for generating electricity.
• Wind Energy: Generated from windmills; used to power homes and industries.
• Biomass Energy: Energy from organic materials like plants and animal waste.

4. Importance of Minerals and Power Sources:

• Industrial Development: Minerals and energy resources are vital for industries.
• Employment: Mining and energy sectors provide numerous jobs.
• Economic Growth: Energy resources are crucial for the overall development of a country.

5. Conservation of Minerals and Power Resources:

• Sustainable Use: Minimize wastage and adopt eco-friendly methods of extraction.
• Alternative Energy: Promote renewable sources of energy to reduce dependency on fossil fuels.

Important Exercises

A. Multiple Choice Questions (MCQs):

1. Which of the following is a non-metallic mineral?

(a) Iron

(b) Gold

(c) Coal

(d) Copper

Answer: (c) Coal

2. Which energy resource is renewable?

(a) Petroleu

(b) Coal

(c) Solar Energy

(d) Natural Gas

Answer: (c) Solar Energy

B. Fill in the Blanks (FIB)

1. Minerals are naturally occurring substances found in the ________. 

Answer: earth's crust

2. ________ is the most abundant fossil fuel used for electricity generation.

 Answer: Coal

3. ________ energy is derived from the heat of the sun.

 Answer: Solar

4. The process of extracting minerals from the earth is called ________. 

Answer: mining

5. ________ and ________ are examples of metallic minerals. Answer: Iron, gold

C. True or False

1. Solar energy is a conventional source of energy.

Answer: False

2. Underground mining involves digging tunnels to extract minerals.

Answer: True

3. Petroleum is a non-renewable energy source.

Answer: True

4. Limestone is a metallic mineral.

Answer: False

5. Biomass energy comes from organic materials like plants and animal waste.

Answer: True

D. Very Short Answer Questions:

1. What are minerals?

Answer: Minerals are naturally occurring substances found in the earth's crust with a definite chemical composition.

2. Name two metallic minerals.

Answer: Iron and Gold.

E. Short Answer Questions:

1. What is open-pit mining?

Answer: Open-pit mining is a method of mining where minerals are extracted by digging from the earth’s surface.

2. Why is it important to conserve minerals?

Answer: It is important to conserve minerals because they are finite resources, and unsustainable use can lead to depletion, affecting industries and future generations.

F. Long Answer Questions:

Q1. Explain the difference between conventional and non-conventional sources of energy with examples.

Answer: Conventional sources of energy include fossil fuels like coal, petroleum, and natural gas, which are non-renewable and pollute the environment. Non-conventional sources include solar, wind, and hydro energy, which are renewable and eco-friendly. Conventional sources are limited and contribute to global warming, while non-conventional sources help in sustainable development.

Q2. Describe the role of minerals and power sources in the development of industries.

Answer: Minerals and power sources are the backbone of industries. Minerals like iron and copper are used as raw materials in manufacturing, while energy sources like coal and petroleum pro

vide power to run machines and transport goods. Without them, industrial growth and economic development would not be possible.