1. Water is essential for life because of the following reasons: (i) Most biological reactions occur when substances are dissolved in water. Thus, all cellular processes need water as a medium to take place. (ii) Transportation of biological substances needs water as a medium. For more answers visit toRead more

    Water is essential for life because of the following reasons:
    (i) Most biological reactions occur when substances are dissolved in water. Thus, all cellular
    processes need water as a medium to take place.
    (ii) Transportation of biological substances needs water as a medium.

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    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-14/

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  2. The atmosphere is essential for life because it maintains an appropriate climate for the sustenance of life by carrying out the following activities: (i) Atmosphere keeps the average temperature of the Earth fairly constant during day time. (ii) It prevents a sudden increase in temperature during daRead more

    The atmosphere is essential for life because it maintains an appropriate climate for the sustenance
    of life by carrying out the following activities:
    (i) Atmosphere keeps the average temperature of the Earth fairly constant during day time.
    (ii) It prevents a sudden increase in temperature during day time.
    (iii) It also slows down the escape of heat from the surface of the Earth into outer space during
    nighttime.

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  3. The two forms of oxygen found in the atmosphere are: (i) Diatomic molecular form with chemical formula O2. (ii) Triatomic molecular form with chemical formula O3 known as ozone. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-14/

    The two forms of oxygen found in the atmosphere are:
    (i) Diatomic molecular form with chemical formula O2.
    (ii) Triatomic molecular form with chemical formula O3 known as ozone.

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    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-14/

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  4. Some gases like carbon dioxide, methane, nitro us oxide prevent the escape of heat from the Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called the greenhouse effect. An increase in the content of such gases would lead to a situation of global warming.Read more

    Some gases like carbon dioxide, methane, nitro us oxide prevent the escape of heat from the
    Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called
    the greenhouse effect. An increase in the content of such gases would lead to a situation of global warming.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-14/

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  5. (i) Burning of fuels in various processes like heating, cooking, transportation, and industry. (ii) Human induced forest fires. (iii) The process of deforestation includes the cutting down of trees. This decreases the uptake of carbon dioxide for photosynthesis. Eventually, the content of carbon dioRead more

    (i) Burning of fuels in various processes like heating, cooking, transportation, and industry.
    (ii) Human induced forest fires.
    (iii) The process of deforestation includes the cutting down of trees. This decreases the uptake of
    carbon dioxide for photosynthesis. Eventually, the content of carbon dioxide increases.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-14/

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