Air Around Us Class 6 notes - Chapter 15

What is the Composition of Air?

Air is present all around us. We can feel the presence of air but cannot see the air around us. Air is a mixture of gases. The different components of air includes – 78% nitrogen, 21% oxygen, 0.9% argon, 0.04% carbon dioxide, and about 1% water vapour. Air plays an important role in breathing and burning. The existence of life on the planet earth is mainly because of the presence of air.

How is the oxygen replaced in the atmosphere?

As we all know, air contains only 21% oxygen. All living organisms including the plants require oxygen for breathing. Plants play an important role in the balance of oxygen and carbon dioxide in the atmosphere and are maintained through the process of photosynthesis.

Photosynthesis is a biological process in which all green plants synthesize their food in the presence of sunlight, water, and carbon dioxide. Oxygen gas is the most important by-products of this process.

Clouds

The vast white fluffy clouds seen in the blue sky is actually millions of tiny water droplets held up by air. The water vapour that evaporates from seas, rivers and other water bodies travels up into the sky to form clouds.

Air is Everywhere

  • Our earth is surrounded by a thin layer of air.
  • We cannot see air, but we can feel its presence in many ways.
  • Leaves of the trees rustle and the branches sway in the wind.
  • The clothes hanging on a clothesline swing because of the presence of air.
  • This layer extends up to many kilometres above the surface of the earth and is called the atmosphere.

Colour of Air

Air has no colour and one can see through it. It is transparent.

Moving Air

Moving air can be termed as the wind. We can feel the wind as it sways leaves on a tree or during storms the wind blows at a very high speed even uprooting trees in their way.

Moving Air - Wind

Atmosphere

The layer of air that covers the Earth extends up to some kilometres in space, this is the atmosphere.

Air as a Mixture

Air is a mixture of different gases and particles; oxygen, water vapour, nitrogen, carbon dioxide, dust and smoke.

Main components of Air

The main constituents of air are nitrogen and oxygen. Air is 78 per cent nitrogen, just under 21 per cent oxygen, and the rest is water vapour, carbon dioxide and small concentrations of other gases.

Water vapour

Water vapour is present in the air as a gaseous form of water and is responsible for humidity.

Dust and smoke

The minor particles that are present in the air. The high amount of these particles in the air can cause pollution.

Breathing in Humans

Both animals and humans breathe by inhaling oxygen and exhaling carbon dioxide. this process is termed as respiration.

Breathing in humans

Breathing in Plants

Plants respire through the process of photosynthesis. In this process, they take in carbon dioxide and give out oxygen as a waste which we breathe in.

Photosynthesis

Photosynthesis is a biological process used by plants to prepare their food with the help of sunlight and energy. Carbon dioxide is taken in and oxygen is given out as a waste product in this process.

Photosynthesis

Breathing in Fish

Oxygen dissolved in water is used by fishes to breathe.

Symbiotic Cycle

  • Organisms usually come together where each benefits from the other.
  • We get oxygen and other products from plants and they get not only carbon dioxide but other advantages from us.
  • This is in the form of a cycle. Respiration and photosynthesis lead to recycling of oxygen and carbon dioxide in the environment.

Fire

Fire requires oxygen for sustenance.

Burning Fire

             

Learn more about the Water from the topics given below:

Leave a Comment

Your email address will not be published. Required fields are marked *