NCERT Solutions Class 9th Science Chapter – 14 Natural Resources Question & Answer

May 26, 2022

NCERT Solutions Class 9th Science Chapter – 14 Natural Resources

Textbook	NCERT
Class	9^th
Subject	Science
Chapter	14^th
Chapter Name	Natural Resources
Category	Class 9^th Science
Medium	English
Source	Last Doubt

NCERT Solutions Class 9th Science Chapter – 14 Natural Resources

Chapter – 14

Natural Resources

Question & Answer

Class 9 Science Chapter 14 Intext Question Page:193

1. How is our atmosphere different from the atmospheres on Venus and Mars?
Answer: Earth’s atmosphere is composed of various gases like oxygen, carbon dioxide, nitrogen, water vapour along with various gases in small quantities, hence making it a balanced composition which is more livable than other planets. Planets like Venus and Mars have more than 95% of carbon dioxide in the air making the existence of life impossible.

2. How does the atmosphere act as a blanket?
Answer: It maintains the consistency in temperature throughout the day making it a comfortable place to stay.The ozone in the atmosphere is responsible for maintaining the temperature without letting the harmful ultra-violet ray affect.

3. What causes winds?
Answer: The uneven heating of the earth’s surface is the main cause for the winds. On being heated more the air raises up and hence low pressure is created. Hence, the air in high pressure occupy the low-pressure region causing the wind.

4. How are clouds formed?
Answer: During the day time in the presence of sunlight water from sources like well, lake, pond, sea, river and various other sources get evaporated and this water vapour rises up with the hot air. At a particular height, the air cools and the water vapour condenses to form minute droplets to form clouds.

5. List any three human activities that you think would lead to air pollution.
Answer: Burning of fuels like petroleum, kerosene, and coal in the atmosphere
The smoke released from manufacturing industries
Smoke from vehicles

Class 9 Science Chapter 14 Intext Question Page:194

1. Why do organisms need water?
Answer: Organisms need water because:
(i) Cellular processes need water for their functioning.
(ii) Substances dissolve in water for reactions to take place within the cells.
(iii) Transportation of substances within the body need water.
(iv) Water helps in digestion of food and its absorption in the blood.

2. What is the major source of fresh water in the city/town/village where you live?
Answer:
1. Rainfall
2. Underground water from wells
3. Water sources like pond, river, and lake
4. Snowfall

3. Do you know of any activity which may be polluting this water source?
Answer:
(i) Dumping waste in the river
(ii) Factory waste
(iii) Sewage

Class 9 Science Chapter 14 Intext Question Page:196

Question 1. How is soil formed ?
Answer: The formation of soil takes place in this way :
Over long periods of time, thousands and millions Of years, the rocks at or near the surface of the are broken down by various physical, chemical and some biological processes. The end product of this breaking down is the fine particles of soil. There are many other factors which play a vital role in the formation of soil. These factors are :
(i) The Sun : It causes heating of rocks which causes cracking and ultimately breaking up into smaller pieces.
(ii) Water: It breaks rocks both by freezing and fast flow.
(iii) Wind : It causes erosion of rocks similar to as done by fast flowing water. It also carries sand from one place to the other like water does.
(iv) Living organisms : Lichens and moss plants grow on the rock surface and cause rock surface to powder down and form a thin layer of soil. The roots of big trees sometimes go into cracks in the rocks and as the roots grow bigger, the crack is forced bigger.

Question 2.What is soil erosion ?
Answer: The removal of topsoil which is rich in humus and nutrients by flowing water or wind is known as soil erosion. If this process continues further then all soil may get washed away and the rocks underneath may get exposed. It may lead to the loss of all valuable resources because nothing grows as such on the rocks.

Question 3. What are the methods of preventing or reducing soil erosion ?
Answer: The methods of preventing soil erosion are :
(i) Afforestation : Forests reduce erosion as the roots of trees hold the soil in place.(ii) Shelter belts : Trees planted in lines or hedges around farmland reduce erosion by reducing the speed of the wind.(iii) Contour ploughing : Farmers plough land so that furrows lie across the natural slope of the land. These furrows trap water and do not allow it to flow down carrying the topsoil.(iv) Terrace (or step) farming : A terraced hillside is less likely to be eroded than a natural hillside. Here a series of steps formed by horizontal strips supported by walls, catch the descending water. It gives the water sufficient time to percolate into the soil and nourish the crop.(v) Soil cover : Soil left bare after harvesting a crop is often covered with dried vegetation to prevent erosion. Steep slopes that cannot be ploughed are covered with grass or pasture crops.(vi) Preventing overgrazing : As the grass has a tendency to bind soil molecules, so even a very little grass on a field prevents erosion of soil. But if the grass is overgrazed, it exposes the soil to erosion.

Class 9 Science Chapter 14 Intext Question Page:201

1. What are the different states in which water is found during the water cycle?
Answer: Water is found in all three states like
(i) A solid-state (Snow, ice)
(ii) Liquid state (river water, underground water)
(iii) Gaseous state (water vapour)

2. Name two biologically important compounds that contain both oxygen and nitrogen
Answer:
(i) DNA (Deoxyribonucleic Acid)
(ii) RNA (Ribonucleic Acid)
(iii) Amino acids

3. List any three human activities which would lead to an increase in the carbon dioxide content of the air
Answer: (i) Breathing process where Carbon dioxide is released
(ii) Burning of petrol, coal, and fuel
(iii) Using fridge, air conditioners and oven

4. What is the greenhouse effect?
Answer: Gases like Carbon dioxide and methane trap sun’s radiation and does not allow it to go back and hence causing warming of the atmosphere, resulting in the greenhouse effect.

5. What are the two forms of oxygen found in the atmosphere?
Answer: Oxygen is present in two form
(i) Diatomic molecular form (O2)
(ii) Triatomic molecular form (O3)

Class 9 Science Chapter 14 Exercise Questions Page:196

NCERT Solution Class 9th Science (Chapter – 14) Question No. 1

1. Why is the atmosphere essential for life?
Answer: The atmosphere is constituted of various main gases like O2, N2, and CO2 which are the basis of living of microorganisms, plants and animals.
Photosynthesis is due to earth’s atmosphere
he constant temperature of the earth is the cause of the earth’s atmosphere
Processes like respiration, burning, and combustion are due to the atmosphere
The atmosphere is the main reason to restrict UV rays into the earth

NCERT Solution Class 9th Science (Chapter – 14) Question No. 2

2. Why is water essential for life?
Answer: Water is essential for life because:
(i) Water forms the major component of a living organism.
(ii) It plays a vital role as all the metabolic processes required for growth and development requires a liquid medium.
(iii) Most of the reactions occur when the substances are in the dissolved state.

NCERT Solution Class 9th Science (Chapter – 14) Question No. 3

3. How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?
Answer: All living organisms on the earth directly or indirectly are dependent on soil for a living. Plants obtain water and minerals through the soil and prepare their food. Other living organisms that live in water are entirely not totally independent of soil because the microbes growing on the soil in water are the primary producers. Primary producers are the main and chief element of the food chain. Various microbes found in soil help in the decomposition of dead plants and animals in water which helps in returning the nutrients and elements back to the water.

NCERT Solution Class 9th Science (Chapter – 14) Question No. 4

4. You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
Answer: Weather is studied as the collection of various elements like high and low temperatures, humidity, rainfall, wind speed and more using various figures and facts with relevant instruments. Hence, on the data collected by the meteorologists, we are able to forecast the weather.

NCERT Solution Class 9th Science (Chapter – 14) Question No. 5

5. We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?
Answer: Human activities are the main reason for the pollution in the air. Air is the medium to spread the pollutants into various sources like water and soil. Hence, we can say that limiting activities certain place will definitely help the air pollution to be controlled to some extent.

NCERT Solution Class 9th Science (Chapter – 14) Question No. 6

6. Write a note on how forests influence the quality of our air, soil and water resources.
Answer:
Air: Forests help in purifying the air by absorbing all kinds of pollutants.
Forests help in increasing the oxygen level in the air by absorbing carbon dioxide during photosynthesis.
Transpiration helps to maintain the temperature of the surrounding and helps in the formation of clouds.

Soil: Plants in forest hold the soil thereby preventing soil erosion. Adds nutrients to the soil as a lot of vegetation present in the forest gets decomposed.

Water: Forest helps in bringing rain and increasing the level of water in underground levels

NCERT Solution Class 9th Science All Chapters Question & Answer