Study MaterialsNCERT SolutionsNCERT Solutions for Class 8 ScienceNcert Solutions for Class 8 Science Chapter 18 Pollution Of Air And Water

Ncert Solutions for Class 8 Science Chapter 18 Pollution Of Air And Water

Class 8 Science Chapter 18 NCERT Solutions – Free PDF Download

NCERT Solutions for Class 8 Science (Chemistry) Chapter 18 – Pollution of Air and Water solved by Expert Teachers as per NCERT (CBSE) Book guidelines are available for free PDF download at, India’s No. 1 online tutoring website. All Exercise Questions with Solutions for Chapter 18 – Pollution of Air and Water to help you revise the entire syllabus and get more marks. Join us for a free webinar with India’s greatest Class 8 Science tutor.

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    Question. What are the different ways in which water gets contaminated?

    Answer. Water gets contaminated due to :

    1. excessive use of pesticides and insecticides.
    2. Discharge of industrial effluents into rivers, lakes, etc.
    3. She was throwing garbage into water bodies.
    4. Leakage of oil into the sea due to damage of ships that transports oil in the large
    5. discharge of effluents into water bodies from slaughterhouses, poultry, dairy farms, etc.

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

    A. An individual can reduce air pollution by :

    1. avoiding using cars as much as possible and using public transport whenever possible.
    2. By not using vehicles for short distances.
    3. I use clean fuels such as LPG and CNG instead of diesel and petrol.
    4. Always dispose of the garbage correctly and not burn it.
    5. They are controlling the emissions from vehicles and household chimneys.

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

    A. i) No, Clear and transparent water is not always fit for drinking.

    ii) Water might appear clean, but it may contain some disease-causing microorganisms and other dissolved impurities.

    iii) Hence, it is advised to purify water before drinking.

    iv) Purification can be done by water purifying systems or boiling the water.

    Question. You are a member of the municipal body of your town. Please make a list of measures to help your town ensure a clean water supply to all its residents.

    A. To ensure the supply of clean water to all residents, the following steps must be taken :

    1. The main water source must be appropriately maintained with built-in clean surroundings.
    2. Chemical methods such as chlorination must be used to purify water.
    3. The area around water pipes must also be clean.

    Question. Explain the differences between pure air and polluted air.


    i) Contains no pollutants. i) Contains pollutants.
    ii) Contains large amounts of oxygen. ii) Contains small amounts of oxygen.
    iii) It is safe to breathe. iii) It is not safe to breathe.
    iv) It does not cause any diseases. iv) It may result in various diseases (especially respiratory).

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

    A. i) Burning fossil fuels such as coal and diesel releases pollutants such as sulphur dioxide and nitrogen dioxide into the atmosphere.

    ii) These pollutants react with water vapours in the atmosphere to form sulphuric acid and nitric acid.

    iii) These acids come down with the rain, resulting in acid rain.

    Effects of acid rain :

    i) Acid rains damage crops.

    ii) Acid rains corrode buildings and structures, especially marble ones like the Taj Mahal.

    Question. Which of the following is not a greenhouse gas?

    1. Carbon dioxide
    2. Sulphur dioxide
    3. Methane
    4. Nitrogen

    A. d) Nitrogen

    Question. Describe the ‘Greenhouse Effect’ in your own words.


    1. The greenhouse effect is caused by greenhouse gases such as carbon dioxide, methane, and water vapour.
    2. When solar radiations reach the earth, some of these radiations are absorbed by the earth and then released back into the atmosphere.
    3. Greenhouse gases in the atmosphere trap these radiations and do not allow heat to escape. This helps keep our planet warm and, thus, helps in human survival.
    4. However, an indiscriminate increase in the number of greenhouse gases can lead to an excessive increase in the earth’s temperature leading to global warming.

    Question. Describe the threat to the beauty of the Taj Mahal.


    1. Acid rain is a major threat to the beauty of the Taj Mahal.
    2. Acid rain corrodes the marbles of this monument. This phenomenon is known as marble cancer.
    3. Also, the soot particles emitted from the Mathura oil refinery near Agra lead to the yellowing of the marble.

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


    1. An increase in the level of nutrients in a water body leads to an excessive increase in the algae population in the water body.
    2. When these algae die, they serve as food for decomposers, like bacteria.
    3. A lot of oxygen is utilized in this process.
    4. This decreases the level of oxygen dissolved in the water body, which may kill aquatic organisms.

    NCERT Solutions for Class 8 Science Chapter 18 – Air and Water Pollution

    The NCERT Grade 8 Science Chapter 18, Pollution of Air and Water, addresses a serious issue and its consequences. The chapter also discusses how to handle the dangerous phenomena of pollution and how individuals might contribute to its decrease. What Causes Air Pollution? How Does Air Become Polluted? What Can Be Done in the Case of the Taj Mahal and the Greenhouse Effect? What Causes Water Pollution and How Does Water Become Polluted? What exactly is potable water, and how is it purified? Some of the important themes explored in this chapter include What Can Be Done? and What Can Be Done?

    Examples and visual representations aid in a better understanding of air and water pollution effects. Students’ learning experiences will motivate them to take action in the fight against pollution. Students benefit from activities and project work since they are eye-opening. Case studies assist students in comprehending the current situation as a result of unchecked levels of air and water pollution. Technical vocabulary learned throughout the chapter, summaries of key themes, and tasks at the end aid with skimming the chapter and self-evaluation. This chapter will introduce pupils to the perils of pollution. It will assist students in gaining a better understanding of the subject and mastering the principles that will enable them to perform better.

    NCERT Solutions for Class 8 Science Chapter 18 (Pollution of Air and Water) explained by qualified Science instructors are 100% accurate. As per CBSE Board requirements, we provide answers to the Class 8 Science textbook questions using the most recent NCERT book for Class 8 Science.

    The following are the subjects and sub-topics in Chapter 18: Pollution of Air and Water.

    1. Ex 18.1 – Pollution of the Air
    2. Ex 18.2 – What Causes Air Pollution?
    3. Exhibit 18.3 – The Taj Mahal as a Case Study
    4. Explanation of Experiment 18.4 – Greenhouse Effect
    5. What Can Be Done in Exhibit 18.5?
    6. Ex 18.6 – Pollution of Water
    7. Ex 18.7 – What Causes Water Pollution?
    8. Ex 18.8: What is potable water, and how is it purified?
    9. Ex 18.9 – Is There Anything That Can Be Done?

    In the following chapter, we will go over all of the exercises: – 11 Questions and Answers in Chapter 18

    In addition to the tasks, you should practice all of the solved cases in the book to solidify your understanding of air and water pollution. Chapter 18: Pollution of Air and Water is available as a free PDF download. Take a printout and keep it with you as you study for your exams.

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