The air around us is a mixture and not a compound. It comprises 21% of oxygen, 78% of nitrogen, & the remaining 1% is a mixture of water vapour, smoke, and dust. Its composition changes at different locations. 

Let’s now understand what air is made up of. This is as follows:

1. Nitrogen – Required by plants for their growth.
2. Oxygen – Used in burning and respiration by all living beings.
3. Carbon Dioxide – This gas is released on burning. Also, when plants and animals consume oxygen for respiration, they produce carbon dioxide in exchange. Green plants also use it for photosynthesis. 
4. Water vapour – It is formed by water evaporation. The amount of water in the air around us is called humidity. It varies at every place.
5. Smoke and Dust – Smoke contains some gases. It also has fine dust particles that are harmful. Remember when our parents scold us when we try to breathe from our mouths? They ask us to breathe from our nostrils. Yes, children breathing through our noses filters oxygen from the air around us. Nostrils hold dust particles to avoid entering them into our lungs. If it enters our lungs, it can make us sick.

Plants and animals are interdependent on earth. How? Plants use carbon dioxide for the preparation of their food during photosynthesis. Plants consume more carbon dioxide from the atmosphere than oxygen. Whereas animals require oxygen for respiration that they take from plants. Animals release carbon dioxide due to the exhalation process of respiration. Plants then consume it. This is how oxygen in the atmosphere is replaced by animal and plant consumption.

Air is present in water in the form of dissolved oxygen. All aquatic animals and plants consume oxygen from dissolved air in water. Similarly, fish take oxygen through their fins underwater.

There are empty spaces that are filled with air in the soil. To understand this, do this activity: Pour some water on the soil. You will see a few bubbles come out first. After which water is soaked by soil. These bubbles are the air that fills space in the soil. So, when there is heavy rain, earthworms come out of their holes. Because the air they were consuming earlier filled in soil space is now filled with water, they don’t have air left in the soil for respiration. This is how oxygen becomes available to animals and plants living in water & soils.

Now, you know that the air around us is essential. We must not pollute the air. Air supports burning fire. It is needed for breathing. Plants are heavily dependent on air to make their food. Birds need air for flying, and you also need to fly your kites. Right? Aeroplanes can only fly because of air pressure. 

Air, when in motion, produces wind. Windmill runs by the wind. A windmill is used to generate electricity. It is used to take out water from a tube well. Air is an essential element in the water cycle. The air around us is an extremely useful natural source that we all are highly dependent on to survive.

What is the air around us called?

It is called the atmosphere.

How do you know that there is air around us? 

With a lot of natural phenomena, we can prove that the air around us is present. Example: wind blowing trees. Another example is when a fan is switched on, your book’s pages start moving independently.

Can you give examples of how the air around us can be? 

The windmill starts rotating its shaft when the air moves. Clothes start swaying & when the trees leave, rustle are few examples of air around us.

Is the air around us a compound or a mixture? 

Air is a mixture of several gases.

What are the five components of air?

Oxygen, Carbon Dioxide, Nitrogen, Water Vapour, Smoke & Dust

What are 20 uses of air?

The 20 uses of air are –

It supports the life of all living beings, helps in growth, used in the photosynthesis process by plants, supplies energy, maintains the temperature, helps in flying kites, participates in cloud formation, used in vehicle tyre & balloon pumping, dispersal of seeds, and pollens, respiration by aquatic animals through dissolved air, drying, generating electricity through windmills, water floating device such as life jackets, used in air cushions & beds, provides oxygen to breathe for living organisms, air balloons, musical instruments such as flute, parachutes, aeroplanes & birds flying.