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Chapter Analysis
Intermediate7 pages • EnglishQuick Summary
Chapter 3 of the Class 8 Science NCERT textbook discusses coal and petroleum as critical fossil fuels. It explains the formation of coal from dead vegetation through the process of carbonization. The chapter examines petroleum's origin from marine organisms and outlines its refining process to produce various usable products. Additionally, the chapter highlights the significance of natural gas, and emphasizes the need for conservation due to the exhaustible nature of these resources.
Key Topics
- •Formation of coal and its uses
- •Formation and refining of petroleum
- •Natural gas as a fuel
- •Conservation of fossil fuels
- •Exhaustible nature of fossil fuels
- •Environmental impact of burning fossil fuels
- •Products derived from coal and petroleum
- •Role of fossil fuels in energy generation
Learning Objectives
- ✓Understand how coal and petroleum are formed and extracted
- ✓Identify the various uses of coal, petroleum, and natural gas
- ✓Explain the process of refining petroleum
- ✓Recognize the environmental impact of fossil fuel consumption
- ✓Learn the importance of conservation of exhaustible resources
- ✓Comprehend the socioeconomic significance of fossil fuels
Questions in Chapter
What are the advantages of using CNG and LPG as fuels?
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Name the petroleum product used for surfacing of roads.
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Describe how coal is formed from dead vegetation. What is this process called?
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Fill in the blanks. (a) Fossil fuels are ____, ____ and ____. (b) Process of separation of different constituents from petroleum is called ____. (c) Least polluting fuel for vehicle is ____.
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Tick True/False against the following statements. (a) Fossil fuels can be made in the laboratory. (b) CNG is more polluting fuel than petrol. (c) Coke is almost pure form of carbon. (d) Coal tar is a mixture of various substances. (e) Kerosene is not a fossil fuel.
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Explain why fossil fuels are exhaustible natural resources.
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Describe characteristics and uses of coke.
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Explain the process of formation of petroleum.
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The following Table shows the total power shortage in India from 1991–1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.
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Additional Practice Questions
What is the process called where coal is formed from dead vegetation over millions of years?
mediumAnswer: The process is called carbonization, where dead vegetation undergoes high pressure and temperature over millions of years to form coal.
How is petroleum formed from marine organisms?
mediumAnswer: Petroleum is formed from marine organisms whose bodies settle at the seabed, getting covered with layers of sand and clay. Over millions of years, the absence of air, high temperature, and pressure transform these into petroleum.
Why is natural gas considered a cleaner fuel compared to other fossil fuels?
easyAnswer: Natural gas is considered cleaner because it produces fewer pollutants, resulting in lower emissions of substances that contribute to air pollution and global warming.
What measures can be taken at an individual level to conserve fossil fuels?
mediumAnswer: Individuals can conserve fossil fuels by driving at a consistent moderate speed, maintaining the correct tire pressure, switching off the vehicle engine when not in use, and ensuring regular vehicle maintenance.
What are the environmental impacts of burning fossil fuels?
hardAnswer: Burning fossil fuels releases significant amounts of carbon dioxide, contributing to global warming and climate change. It also produces pollutants that harm air quality and public health.
Discuss the significance of CNG in urban transportation.
mediumAnswer: CNG is significant in urban transportation due to its efficiency and low emission profile, offering a cleaner alternative to gasoline or diesel, thus reducing urban air pollution.
Compare and contrast the uses of coal and petroleum.
mediumAnswer: Coal is mainly used for electricity generation and industrial processes, whereas petroleum is used in transportation and as a raw material for various chemical products. Both are crucial but have different applications based on their properties.
What are petrochemicals, and why are they important?
easyAnswer: Petrochemicals are chemical products derived from petroleum and natural gas. They are essential for producing plastics, synthetic fibers, and numerous other materials that are fundamental to modern industries.
Outline the steps in refining crude oil.
hardAnswer: Crude oil is refined in a distillation process where it is heated in a furnace, separating it into fractions like gasoline, diesel, and other products based on different boiling points.
Why should the use of fossil fuels be minimized?
mediumAnswer: Minimizing fossil fuel use reduces the risk of resource exhaustion, decreases air pollution, mitigates climate change impacts, and promotes the sustainability of the environment.
NCERT Exemplar
AvailablePractice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.
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