CBSE Class 8 Science Chapter 3 Coal And Petroleum SAQs

CBSE Class 8 Science Chapter 3 Coal And Petroleum Short Answer Questions

Question 1. Some natural resources are given below. Classify them into the exhaustible and inexhaustible natural resources.
Air, coal, natural gas, sunlight, petroleum, minerals, forests, oxygen
Answer: Exhaustible natural resources are coal, natural gas, petroleum, minerals, and forests. Inexhaustible natural resources are air, sunlight, and oxygen.

Question 2. Sunlight and air are inexhaustible natural resources. Comment.
Answer: These resources are present in an unlimited quantity in nature and are not likely to be exhausted by human activities.

” Formation Of Coal Class 8 “

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Question 3. You are provided with a mixture of petroleum and water. Can you suggest a method to separate the two?
Answer: Decantation can be used to separate a mixture of petroleum and water. The mixture is allowed tostand. Carefully, lighter layer can be poured and separated without disturbing the heavier one.

” Cbse Class 8 Science Chapter 3 Saqs “

Question 4. Write the name of the products obtained when coal is heated strongly in the absence of air.
Answer: When coal is heated strongly in the absence of air in closed retorts, various useful products are obtained. These are coke, coal tar, and coal gas.

Question 5. Why should we use petrol or diesel only when necessary?
Answer: We should use these fuels only when necessary because

1. It will reduce air pollution and thus lead to a better environment.
2. It will reduce the risk of global warming.
3. It will ensure their availability for a longer period.

Question 6. Where do we get coal from and how Is It formed?
Answer: About 300 million years ago, the Earth had dense forests in low-lying wetland areas. Due to natural processes like flooding, these forests got buried under the soil and deposited as fossils. Due to high temperature and pressure, dead plants slowly converted into coal.

” Coal And Petroleum Class 8 “

Question 7. Write the difference between coke and coal.
Answer: The Differences between coke and coal are as follows

” Exhaustible And Inexhaustible Resources “

Question 8. Write the characteristics and some important uses of coal.

Answer:

Characteristics of coal are as follows:

1. Coal is a hard, black combustible fuel.
2. It is a fossil fuel.
3. It mainly contains carbon.
4. When heated in air, coal burns and produces mainly carbon dioxide gas.
5. It is a source of energy