Air We Breathe Book Back Answers & Guides

Unit 3 > Science > Class 4 > Samacheer Kalvi - English Medium

    Choose the correct answer

  • 1. Air is a ___________.

    (a) Mixture

    (b) Compound

    (c) Complex

    Correct answer:

    (a) Mixture

    View explanation


  • 2. Percentage of Oxygen in air is about ___________%.

    (a) 21

    (b) 78

    (c) 1

    Correct answer:

    (a) 21

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  • 3. Root nodules of some plants contain ___________.

    (a) Oxygen

    (b) Nitrogen

    (c) Neon

    Correct answer:

    (b) Nitrogen

    View explanation


  • 4. The major cause of air pollution is ___________.

    (a) Waste

    (b) Smoke

    (c) Water vapour

    Correct answer:

    (b) Smoke

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  • Who am I?

  • 1. I am a mixture of gases.

    Correct answer:

    air

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  • 2. I give you oxygen.

    Correct answer:

    Plants

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  • 3. I am not the supporter of burning

    Correct answer:

    water

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  • 4. You can help me to decrease pollution by riding on me.

    Correct answer:

    Bicycle

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  • True or false

  • 1. Plants need nitrogen for their growth.

    Correct answer:

    TRUE

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  • 2. Air is made up of oxygen only.

    Correct answer:

    FALSE

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  • 3. The gas used for burning things is Argon.

    Correct answer:

    FALSE

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  • 4. Carbonated drinks are bad to health.

    Correct answer:

    TRUE

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  • Match the following

  • 1. Nitrogen

    Correct answer:

    78%

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  • 2. Balloon

    Correct answer:

    Air

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  • 3. Smog

    Correct answer:

    Smoke and fog

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  • 4. Lung cancer

    Correct answer:

    Air pollution

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  • Fill in the blanks

  • 1. Air is a mixture of many ___________.

    Correct answer:

    gases

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  • 2. Amount of carbon dioxide in the air is ______%.

    Correct answer:

    0.03

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  • 3. We inhale ___________ gas.

    Correct answer:

    Oxygen

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  • 4. _______ is used in fire extinguishers.

    Correct answer:

    Carbon dioxide

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