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Breath of Life: Air

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Air: An Introduction

IVSAT 2024

Do you know why it becomes very difficult for us to breathe as we go to higher altitudes? It is because as we go to higher altitude, air pressure gets very less, and as a result, the amount of oxygen is reduced, and we start feeling altitude sickness. Do you know the composition of air? Which gas is present in a larger amount of air?

Air is a mixture of various gases. Nitrogen is present in large amounts of air, and some gases, such as helium and argon, are present in very few amounts.

What is Air?

Air is a mixture of various gases such as nitrogen, oxygen, other gases, water vapours, and dust particles. It is colourless and odourless. The movement of air from a high-pressure zone to a low-pressure zone is called wind.

Composition of Air 

Air is a mixture of many gases. The percentage of these gases also varies. Percentages of gases present in the air are given below: 

  • Nitrogen - 78% of air is made of nitrogen gas. 

  • Oxygen - 21% of air made of oxygen. 

  • Other gases - 1% of other gases made air. Other gases include carbon dioxide, argon, etc.

Importance of Air

Air has many importances. Some of the importance is given below:

  • Air helps maintain the temperature of the earth by circulating the hot and cold air.

  • The water cycle also maintain by the circulation of air.

  • Moving air also helps in the locomotion and flight of insects and birds.

  • Nitrogen gas is used by plants to make amino acids and proteins.

  • Seeds dispersed from one place to another place with the help of air.

  • Oxygen is inhaled from the air while breathing.

  • The ozone layer protects animals and plants from ultraviolet radiation.

  • Air is the most important element for sustaining life on earth.

Role of Air in Human Life

  • Oxygen is the most important gas for the survival of human beings, it assists in respiration, and oxygen helps in the combustion of food, from which ATP is released.

  • Ozone protects us from harmful radiation.

Air Pollution and Its Side Effects

Air pollution is defined as undesirable changes in the quality of air. It may be a physical, chemical, and biological change in the air quality.

  • There are various bad impacts of air pollution on human health.

  • It causes acid rain, which can damage monuments, plants, and animals.

  • It can also deplete the ozone layer, which leads to the entry of harmful ultraviolet radiation and cause various types of diseases in humans, such as cancer or skin diseases.

  • If the carbon monoxide level is high in the air, it can cause various harm to live organisms. It is a highly poisonous gas that binds to haemoglobin and reduces the oxygen-carrying capacity of the haemoglobin molecule.

  • It can cause various respiratory diseases such as asthma, shortness of breath.

  • It can also damage plants, and their chlorophyll.

Interesting Facts

  • Our lungs can hold up to seven litres of air.

  • Most oxygen in our atmosphere is obtained from oceans and seas.

  • Beijing cough is a disease in China caused due to increased pollution.

  • More than 65% of deaths in Asia caused due to air pollution.

  • Almost 80% of respiratory diseases occur due to air pollution.

  • Pollen grains of flowers can also contribute to air pollution.

Important Questions

Q1. Who discovered oxygen?

Ans: Oxygen was discovered by Joseph Priestley in 1774. It is used for breathing and is responsible for the burning of substances.


Q2. What gases do we inhale and exhale?

Ans: We inhale oxygen and exhale carbon dioxide while breathing. Air contains 21% oxygen, and less than 0.03% of carbon dioxide is present in the air.


Q3. What has caused air pollution?

Ans: Substances that cause air pollution are known as air pollutants. This pollutant is released into the air due to the burning of fossil fuel, from vehicles, or emitted from industries and agriculture.

Key Features

  • In this article, we have discussed air which is also regarded as the breath of life, the composition of air, etc.

  • The importance of air is maintaining the temperature of the earth, wind also blows due to the locomotion of air, and many other importances have been discussed in this article.

  • Air is composed of nitrogen, oxygen, carbon dioxide, argon, and helium.

  • Air pollution is defined as undesirable changes in the quality of air. It has many side effects, such as causing damage to buildings, monuments, plants, and animals.

Practice Questions

Q1. Which gas is regarded as the breath of life?

Q2. Is the breath of life energy?

Q3. Do we breathe the same air as our ancestors?

Q4. Why is the air we breathe so important?

Q5. Do we breathe to live?

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FAQs on Breath of Life: Air

1. Why is air called the breath of life?

Air is called the breath of life because it contains various essential gases for human life. It contains gases such as oxygen, carbon dioxide, etc. Oxygen is a gas that is inhaled by living organisms, and this oxygen is used to make ATP energy which is the energy currency of the cell. Carbon dioxide is released from plants as a by-product of respiration which is utilised by plants to carry out photosynthesis. Products of photosynthesis are used in plant growth.

2. Describe the biological importance of air in plants.

There are many importances of air in plants, such as: 

  • Plants need oxygen for respiration, oxygen is used to produce ATP, which is then utilised to carry out various functions in plants 

  • Carbon dioxide is used by plants to carry out photosynthesis. 

  • In plants, each part takes care of its need for gaseous exchange. As leaves have stomata for gaseous exchange, stems have lenticels.

  • The plant uses different microbes for nitrogen fixation.

  • Then this fixed nitrogen is used to make different amino acids and proteins.

3. Explain what the atmosphere is and its importance.

  • The atmosphere is defined as the envelope of air present around the earth. These envelopes extend up to several kilometres in height. 

  • This atmosphere is divided into many layers. These layers are - the troposphere, stratosphere, mesosphere, thermosphere, and the last layer is the exosphere now, as we go higher density of layers decreases. The troposphere is the lowest layer that contains air, air comprises many gases such as nitrogen, oxygen, and other gases. Biotic components interact with the atmosphere to make an environment.

  • The atmosphere contains ozone which protects us from harmful ultraviolet radiation.


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