NCERT Class 9 Science Solutions: Chapter 14 Natural Resources –Part 3

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Q 2 Image Showing Soil erosion.

Q 2 Image Showing Soil Erosion

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Question 2:

Q. What is soil erosion?

Answer:

The blowing away or washing away of land surface by wind or water is known as soil erosion.

Question 3:

Q. What are the methods of preventing or reducing soil erosion?

Answer:

The methods of preventing or reducing soil erosion are:

(i) Prevention of deforestation

(ii) Plantation of trees and plants

(iii) Prevent excessive grazing

Question 1:

Q. What are the different states in which water is found during the water cycle?

Answer:

During the water cycle, water is found in solid state (snow, ice, etc.), liquid state (ground water, river water, etc.), and gaseous state (water vapours).

Question 2:

Q. Name two biologically important compounds that contain both oxygen and nitrogen.

Answer:

Two biologically important compounds that contain both oxygen and nitrogen are:

(i) Amino acids

(ii) Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

Question 3:

List any three human activities which would lead to an increase in the carbon dioxide content of air.

Answer:

(i) Burning of fuels in various process like heating, cooking, transportation, and industry.

(ii) Human induced forest fires

(iii) The process of deforestation includes the cutting down of trees. This decreases the uptake of carbon dioxide for photosynthesis. Eventually, the content of carbon dioxide increases.

Question 4:

Q. what is the greenhouse effect?

Answer:

Some gases like carbon dioxide, methane, nitrous oxide prevent the escape of heat from the Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called the greenhouse effect. An increase in the content of such gases would lead to situation of global warming.

Question 5:

Q. What are the two forms of oxygen found in the atmosphere?

Q 5 Image Showing Oxygen And Ozone.

Q 5 Image Showing Oxygen and Ozone

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Answer:

The two forms of oxygen found in the atmosphere are:

(i) Diatomic molecular from with chemical formula

(ii) Triatomic molecular form with chemical formula known as ozone.