NCERT Solutions | Class 8 Science Chapter 18 | Pollution of Air and Water

CBSE Solutions | Science Class 8

Check the below NCERT Solutions for Class 8 Science Chapter 18 Pollution of Air and Water Pdf free download. NCERT Solutions Class 8 Science were prepared based on the latest exam pattern. We have Provided Pollution of Air and Water Class 8 Science NCERT Solutions to help students understand the concept very well.

NCERT | Class 8 Science

NCERT Solutions Class 8 Science
Book:	National Council of Educational Research and Training (NCERT)
Board:	Central Board of Secondary Education (CBSE)
Class:	8th
Subject:	Science
Chapter:	18
Chapters Name:	Pollution of Air and Water
Medium:	English

Pollution of Air and Water | Class 8 Science | NCERT Books Solutions

You can refer to MCQ Questions for Class 8 Science Chapter 18 Pollution of Air and Water to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

NCERT TEXTBOOK EXERCISES

ncert science class 8 pdf free download, Question 1.

What are the different ways in which water gets contaminated?

cbse science class 8 solutions, Answer :

Water gets contaminated due to the addition of substances harmful to health. Sewage, agricultural chemicals, and industrial waste are some of the major contaminants of water.

ncert science class 8 solutions, Question 2.

At an individual level, how can you help to reduce air pollution?

ncert class 8 science Chapter 18 question answer, Answer :

At the individual level we can do the following things to reduce air pollution:

Use CNG and unleaded petrol instead of ordinary petrol and diesel.
Use public transport as far as possible.
Generate awareness about air pollution among the members of our family and friends.
We can plant trees and nurture the ones already present in the neighborhood.

ncert science class 8 textbook pdf, Question 3.

Clear, transparent water is always fit for drinking. Comment.

cbse science class 8 solutions, Answer :

No, water which looks clean may still have disease-carrying microorganisms and dissolved impurities. Hence, it is not always fit for drinking, so it is essential to purify water before drinking, say for example by boiling process.

NCERT Solutions for Class 8 Science, Question 4.

You are a member of the municipal body of your town. Make a list of measures that would help your town to ensure the supply of clean water to all its residents.

ncert class 8 science Chapter 18 question answer, Answer :

Following are some of the measures that would help our town to ensure the supply of clear water to all its residents:

Make the supply system leakproof as a lot of drinking water is being wasted through the leakages.
Proper cleaning of the water tank from time to time.
Chlorine tablets should be made available.
The water supply pipes should not come in contact with the sewage pipes.

NCERT Solutions for Class 8 Science Chapter 18, Question 5.

Explain the differences between pure air and polluted air.

cbse science class 8 solutions, Answer :

Pure air is free from any pollutant, has no smell, is soothing, and not irritating to the eyes. Whereas polluted air gives a filthy smell and people cannot breathe in ut. If people inhale such (impure or polluted) air, they may suffer from various breathing, heart, and lung problems. Even sometimes people die inhaling polluted air.

science class 8 Chapter 18, Question 6.

Explain circumstances leading to acid rain. How does acid rain affect us?

ncert class 8 science Chapter 18 question answer, Answer :

Pollutants like sulphur dioxide and nitrogen dioxide react with the water vapour present in the atmosphere to form sulphuric acid and nitric acid. These come down with the rain, making the rain acidic. This is called acid rain.
Acid rain affects us in many ways, e.g.

Acid rain removes basic nutrients such as calcium from the soil.
Acid rain increases the corrosion of metals.
Acid rain damages buildings and sculptural materials.
The low pH of add rainwater changes the rate of metabolism of some organisms.
Add rain causes damage to freshwater life, e.g., decrease in fish population of lakes.
Add mists cause direct damage to the leaves of plants.

science class 8 pdf, Question 7.

Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Sulphur dioxide
(c) Methane
(d) Nitrogen

cbse science class 8 solutions, Answer :

(d) Nitrogen

cbse class 8 science book, Question 8.

Describe the ‘Green House Effect’ in your own words.

ncert class 8 science Chapter 18 question answer, Answer :

The sun’s rays when fall on the earth’s surface, warm it. Some of the sun’s rays are absorbed by the earth’s surface and left out rays are reflected back into space. Some of these rays are trapped by gases like C0₂, methane, etc. in the atmosphere, and these are not allowed to go out of the earth’s atmosphere.

These trapped rays begin to warm the earth’s surface. This causes heating of the earth’s atmosphere. This effect is named the Greenhouse effect because this is exactly like the greenhouse effect in a nursery.

cbse class 8 science Chapter 18, Question 9.

Prepare a brief speech on global warming. You have to deliver the speech in your class.

cbse science class 8 solutions, Answer :

Today, global warming has appeared as one of the most severe threats to humankind. On one hand, carbon dioxide is added to the atmosphere due to human activities, by the other, as forest areas are also decreasing.

cbse class 8 science notes pdf, Question 10.

Describe the threat to the beauty of the Taj Mahal.

ncert class 8 science Chapter 18 question answer, Answer :

Over the past 2 decades, India’s most famous tourist attraction, the Taj Mahal located at Agra, has become a matter of great concern. Experts have warned that air pollution is discolouring its white marble. So it is not only living organisms that get affected by polluted air but also the non-living things like buildings, monuments, and statues that are going to be affected.

The industries located in and around Agra like rubber processing, automobiles, chemicals and especially, the Mathura Oil Refinery have been responsible for producing pollutants like sulphur dioxide and nitrogen dioxide. These gases react with the water vapour present in the atmosphere to form sulphuric acid and nitric acid. These come down with the rain, making the rain acidic. This is called acid rain. Acid rain has resulted in corrosion of the marble of the monument. The phenomenon is also called “Marble cancer”. Suspended particulate matter, such as the soot particle emitted by the Mathura oil refinery, has contributed to the yellowing of the marble.

The Supreme Court has taken several steps to save the Taj Mahal. It has issued orders for the industries to either switch to cleaner fuels like CNG (Compressed Natural Gas) and LPG (Liquefied Petroleum Gas) or to move to faraway places. Moreover, the automobiles should switch over to unleaded petrol in the Taj Mahal Zone.

cbse class 8 science syllabus pdf, Question 11.

Why does the increased level of nutrients in the water affect the survival of aquatic organisms?

cbse science class 8 solutions, Answer :

Chemicals used as fertilizers in agriculture dissolve in water and are washed away into water bodies from the field. The excessive quantities of chemicals like nitrates and phosphates which are present in fertilisers act as nutrients for algae to flourish. Once these algae die, they serve as food for decomposers like bacteria. They use up a lot of oxygen. This results in a decrease in the oxygen level which is harmful to the survival of other organisms.