NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources, contains solutions to various questions in Exercises for Chapter 14. Natural Resources Class 9 NCERT Solutions have been explained in a simple and easy to understand manner. We are providing NCERT Solutions for Class 9 all subjects which can be accessed by clicking here.
NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources – NCERT Exercises
NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources, Exercises includes all in text and exercise solved questions which helps you to understand the topic covered in Chapter 14 Natural Resources, in a better manner to help you to score good marks in your examinations.
NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources – Intext Questions: Page No. 193
1. How is our atmosphere different from the atmosphere on Venus and Mars?
The atmosphere of Earth contains a mixture of gases: nitrogen (78%), oxygen (21%), carbon dioxide (0.03%) and water vapours.
While the atmosphere of Venus and Mars mainly contain carbon dioxide (95-97%).
2. How does the atmosphere acts as a blanket?
Atmosphere acts as a protective blanket and covers the Earth. Air is a bad conductor of heat. So, it keeps the temperature of Earth fairly steady during the course of whole year. Also, ozone layer acts as a protective shield and protects the Earth from harmful UV rays of the Sun.
3. What causes winds?
The uneven heating of the atmosphere in different regions of the Earth causes winds. The rotation of the Earth and the presence of mountain ranges also help in the formation of winds.
4. How are clouds formed?
Water bodies are heated due to the solar radiation and a large amount of water in the form of water vapour goes into the air.
Air also gets heated due to sunlight and rises up along with the water vapours. As the air rises up, it expands and cools. This cooling causes water vapours to condense in the form of tiny droplets.
Collection of these tiny droplets leads to the formation of clouds.
5. List any three human activities that you think would lead to air pollution?
Following activities would lead to air pollution:
i. Excessive burning of fossil fuels like coal and petroleum lead to the formation of oxides of nitrogen and sulphur. These oxides mix with air and cause acid rain.
ii. Many industries release high amount of poisonous gases like carbon monoxide (CO) into the atmosphere.
iii. Forest fires and excessive use of chlorofluorocarbons(CFCs) also causes emission of harmful gases leading to air pollution.
NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources – Intext Questions – Page No. 194
1. Why do organisms need water?
Organisms need water because:
i. It provides a medium for all the cellular processes to take place.
ii. It is necessary for transport of substances from place to another within the body.
iii. It helps to maintain the body temperature.
iv. It also keeps a balance of salts within the body.
2. What is major source of freshwater in the city/ town/ village where you live?
The major source of freshwater in my locality is underground water. It is drawn with the help of hand pumps and tube. The other nearby freshwater sources are lakes, rivers and ponds.
3. Do you know any activity which may be polluting any water source?
The activities which may be polluting water sources are:
i. Dumping of sewage and other wastes into the water bodies.
ii. Percolation of fertilizers from field into water.
iii. Release of hot water from industries into the water bodies.
Page No. 196
1. How is soil formed?
For millions of years, rocks at or near the surface of the Earth are broken down by various physical, chemical and biological processes. The end product of this breaking down are the fine particles of soil.
2. What is soil erosion?
The removal of the top layer of soil that is rich in organic matter due to strong winds or fast running water is called soil erosion. It results in reduction of soil fertility.
3. What are the methods of preventing or reducing soil erosion?
Preventive measures of soil erosion are:
i. Afforestation: Planting more and more trees reduces soil erosion.
ii. Step farming: It is also known as terrace farming and gives the water sufficient time to percolate into the soil.
iii. Contour ploughing: Ploughing land in furrows across the natural slope of the land helps to trap water and prevents the washing away of topsoil.
iv. Controlled grazing: Grasses tend to bind the soil particles to prevent their erosion. Therefore, excessive grazing should be prevented.
Page No. 201
1. What are the different states in which water is found during the water cycle?
Water can be seen in water cycle in all the different states, these are:
i. Gaseous state: It occurs in the form of water vapours. Water evaporates from the surface of water bodies and mixes with air.
ii. Liquid state: Water vapours condense in the atmosphere and fall on the Earth in the form of rain.
iii. Solid state: It is formed by the freezing of water droplets in the upper layer of atmosphere. These droplets then fall on the Earth in the form of snow, hail, etc
2. Name two biologically important compounds which contain both nitrogen and oxygen?
Two biologically important compounds which contain both nitrogen and oxygen are proteins and nucleic acids (DNA and RNA).
3. List any three human activities which would lead to an increase in the carbon dioxide content of air.
Activities which would lead to an increase in the carbon dioxide content of air are:
i. Burning of forests: It is related to agricultural practices and releases CO2 into the atmosphere.
ii. Deforestation: It also leads to the increase in the level of CO2 in the environment. It is because plants convert CO2 into organic compounds by the process of photosynthesis. In their absence, CO2 can’t be utilized.
iii. Combustion of fuels: Excessive burning of fuels for activities like cooking, transportation, etc leads to increase in the level of CO2.
4. What is the greenhouse effect?
Greenhouse effect is a natural phenomenon that is responsible for heating Earth’s surface and atmosphere due to presence of certain gases in the atmosphere.
In the absence of greenhouse effect, average Earth’s temperature would have been chilly (-18°C) rather than the present average temperature of 15°C.
5. What are the two forms of oxygen found in the atmosphere?
The two forms of oxygen found in the atmosphere are:
i. Elemental Oxygen: It is found in the form of diatomic molecule (O2) in the lower part of the atmosphere. It is non-poisonous form of oxygen.
ii. Ozone: It exists in the stratosphere. It consists of three molecules of oxygen (O3). It is poisonous form of oxygen.
NCERT Solutions for Class 9 Science Chapter 14 – Natural Resources – NCERT Exercise: Page No. 201 and 202
1. Why is the atmosphere essential for life?
Atmosphere is essential for life due to the following reasons:
- It keeps average temperature of earth steady throughout the year
- It prevents sudden increase in temperature during the day.
- It contains gases like oxygen, carbon dioxide and nitrogen which are essential for sustaining life on the Earth.
- A thick layer of ozone prevents harmful UV rays from reaching the Earth.
2. Why is water essential for life?
Water is essential for life due to the following reasons:
- It provides a medium for all the cellular processes to take place.
- It is necessary for transport of substances from place to another within the body.
- It helps to maintain the body temperature.
- It also keeps a balance of salts within the body.
3. How are living organisms dependent on soil? Or Are living organisms that live in water totally independent on soil as a resource?
Living organisms depend on soil for the following reasons:
- It provides natural habitat for many living organisms like bacteria, algae, fungi, earthworm etc. These help to maintain the fertility of the soil.
- It provides nutrient to all living organisms.
- Soil helps to bind the roots of plants and provides them anchorage.
- The nutrients in soil are absorbed by plants for their growth and development.
4. You have seen weather reports on television and newspaper. How do you think we are able to predict the weather?
Meteorologists collect information regarding the pattern of temperature, speed of wind, air pressure etc. All these information are collected by remote sensing and weather forecast satellites. This information is then compiled in meteorological departments. A weather report then prepared and displayed on maps.
5. We know that many human activities lead to increase in 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?
Isolating these activities to specific and limited areas would definitely help in reducing pollution to some extent.
- If the sewage and garbage are collected at an isolated area and treated properly before discharging into water sources, it will reduce water pollution.
- If the commercial areas (factories and industries) are shifted to isolated areas, away from residential areas, it can reduce the impact of air pollution on people.
- If hot water generated from factories is collected at an isolated area and allowed to cool before discharging into water bodies, it will not affect the aquatic life.
6. Write a note on how forests influence the quality of our air, water and soil resources?
Forests influence the quality of air, water and soil resources in the following ways:
i. Impact on the quality of air:
Forests maintain a balance between oxygen and carbon dioxide in the air. They also increase the rate of photosynthesis in the surrounding region.
ii. Impact on the quality of water:
Trees help to maintain water cycle. Forests also conserve water and make it available on earth in the form of rain.
iii. Impact on the quality of soil:
Roots of trees bind the soil particles firmly and thus prevent soil erosion.
Topics Covered in Natural Resources Class 9 Science
- The Breath of Life: Air
- THE ROLE OF THE ATMOSPHERE IN CLIMATE CONTROL
- THE MOVEMENT OF AIR: WINDS
- AIR POLLUTION
- Water: A Wonder Liquid
- WATER POLLUTION
- Mineral Riches in the Soil
- Biogeochemical Cycles
- THE WATER-CYCLE
- THE NITROGEN-CYCLE
- THE CARBON-CYCLE
- THE OXYGEN-CYCLE
- Ozone Layer