CBSE Class 6 Science Revision Notes Chapter 15

CBSE Class 6 Science Chapter 15 Revision Notes – Air Around Us

Class 6 Science Chapter 15 Notes on Air Around Us discusses the important concepts of the main components of air, different layers of the atmosphere, and the importance of air. The chapter is very important for students to master to score better on their exams. Students are advised to read these Revision Notes along with the NCERT text to have a thorough understanding of all the concepts in this chapter.

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Revision Notes for CBSE Class 6 Science Chapter 15

Access Class 6 Science Chapter 15 – Air Around Us Notes

  • The main components of air, an invisible gaseous substance that surrounds the earth, are oxygen and nitrogen.
  • The term “atmosphere” describes the layer of air that envelops the entire planet.
  • Air is present everywhere. We can feel air even though we cannot see it.
  • The wind is air in motion.
  • Air occupies space and is present in both water and soil.
  • The gases that make up the air include nitrogen, oxygen, carbon dioxide, water vapour, a few other gases, and some dust.
  • The environment is essential for life on Earth.
  • Aquatic species breathe dissolved air in the water, whereas plants and animals depend on one another to exchange oxygen and carbon dioxide from the atmosphere.

Different Layers of Atmosphere

  1. Troposphere 
  2. Stratosphere 
  3. Mesosphere 
  4. Thermosphere 

Constituent of Air

Nitrogen and oxygen are the two primary components of air. Approximately 78% of the air is composed of nitrogen. The oxygen content of the air that humans breathe is almost 21%. The remaining 1% of gases includes carbon dioxide, water vapour, dust particles, and other gases. Different parts of the world have different air compositions.

Nitrogen: Nitrogen is made accessible to plants through a sequence of microbial processes that allow plants to grow. Oxygen: All living things rely on oxygen to breathe. Oxygen also aids in burning.

Carbon dioxide: As plants and animals breathe, carbon dioxide is produced from the oxygen they take in. Green plants carry out photosynthesis using carbon dioxide. Carbon dioxide is released during burning.

Water Vapour: Water vapour is formed when water evaporates.The amount of water vapour in the air is referred to as humidity. It varies from place to place and within a single location, both day and night.

Dust and smoke: Smoke contains a few gases in addition to tiny dust particles that are quite dangerous. The concentration of dust particles in the air varies over time and between locations.

 Importance of Air

Air is a thin layer that we can’t see but can feel that covers our planet. Air is essential for all living beings on earth to breathe.

Uses of Air

  • Air exerts force on objects that come in its way. This property of air is quite useful.
  • Fun like firkins, pinwheels are based on the force applied by air.
  • The air current makes the windmills rotate.
  • Air helps in the movements of sailing yachts, sliders, parachutes and aircraft.
  • Air also helps in dispersal of seeds and pollen of flowers.
  • Compressed air is used in tires of vehicles.
  • Nitrogen is used on a large scale to manufacture fertilisers.
  • Winnowing is possible only because of the air.
  • Air is also useful for playing several musical instruments.

Balance Of Oxygen And Carbon Dioxide In The Air

The balance of oxygen and carbon dioxide in the atmosphere is maintained by photosynthesis in plants and respiration in animals. Plants generate oxygen during photosynthesis and use it during respiration. During photosynthesis, they produce far more oxygen than they consume during respiration. Through photosynthesis, the oxygen consumed by plants and, to a lesser extent, animals is replenished in the air.

Air Pollution

Pollution is defined as the addition of substances to the environment in quantities that are harmful to living beings. Due to various human activities, the air is becoming increasingly polluted. The major causes of air pollution are the combustion of fuels such as coal and petroleum, excessive combustion of fuels such as wood, smoke and harmful gases released from industries, smoke released by vehicles and machines emitting gases. These gases spread and mix in the air, degrading its quality and making it impure.

Air pollution has serious consequences for plants, animals, and humans. The presence of harmful gases in polluted air makes breathing difficult. Air pollution is also linked to a variety of lung diseases, including asthma and lung cancer.

There are several methods for reducing air pollution. Some of them are: planting more trees, recycling plastics, regularly inspecting vehicles for harmful gas emissions, and so on.

FAQs (Frequently Asked Questions)

1. What constitutes air?

We can feel the air around us even though we cannot see it. Air is 78% nitrogen, 21% oxygen, 0.9% argon, 0.04% carbon dioxide, and 1% or so water vapour.In both breathing and burning, air is crucial. The presence of air is primarily responsible for life’s existence on Earth.

2. Describe “air pollution".

 Any agent that alters the natural properties of the atmosphere, whether it be chemical, physical, or biological, is considered an air pollutant. Air pollution can occur indoors or outdoors.

3. What can be done to stop "air pollution"?

Some steps to reduce air pollution are as follows.

  1. Reduce the unnecessary usage of vehicles.
  2. Eliminate fireplaces in houses.
  3. Use different cleaning techniques instead of burning grass or leaves.

4. What does "Nitrogen Cycle" mean?

The nitrogen cycle is a biogeochemical process that changes nitrogen from one chemical form to another as it moves through the atmosphere, terrestrial ecosystems, and marine ecosystems.