DAV Class 5 Science Chapter 10 Notes – Air

These DAV Class 5 Science Notes and DAV Class 5 Science Chapter 10 Notes – Air act as excellent revision resources, particularly in preparation for board exams.

Air Class 5 DAV Notes

→ Air: Air is a mixture of gases. Pure air is colourless, odourless and tasteless.

Importance of Air:

  • All animals need oxygen to live. All animals take oxygen during breathing. This oxygen is utilized by the body to produce energy.
  • Oxygen is required for burning anything.
  • Plants also need air for respiration.
  • Plants need carbon dioxide for making their own food by the process of photosynthesis.

→ Nature Maintains a Balance
All animals use oxygen during respiration and give out carbon dioxide. Plants take up carbon dioxide during photosynthesis and release oxygen. Thus, a balance between carbon dioxide and oxygen is maintained in the air.

Pollution of Air:
→ When air has a high percentage of harmful gases, it is called polluted air. Carbon monoxide and oxides of nitrogen and sulphur are examples of harmful gases. Apart from them; dust and soot also pollute the air.

→ Causes of Air Pollution:

  • Dust raised from the ground during a dust storm
  • Stone dust produced during crushing of stones in quarries,
  • Smoke from vehicles, factories and forest fires,
  • Germs from coughing and sneezing results in air pollution.

Effects of Air Pollution:
→ By breathing in polluted air, we may suffer from serious problems like cough, headache, skin disease and eye disease.

DAV Class 5 Science Chapter 10 Notes - Air

→ Oxides of nitrogen and sulphur mix with rainwater and form acid rain. The acid rain damages crops and reduces fertility of soil. Acid rain also damages monuments and buildings.

→ Increased level of carbon dioxide increases overall temperature of the earth. This is called global warming. Global warming is causing melting of polar ice-caps. This can cause huge damage and destruction.

Ways to Reduce Air Pollution:

  • Plant more trees
  • Reduce the use of vehicles
  • Regular check up of vehicles.
  • Use of cleaner fuels.
  • Dumping the garbage in a pit.
  • Constructing tall chimneys.
  • Good habits

→ Acid Rain: When rainwater gets mixed with acidic gases, it is called acid rain.

→ Greenhouse Effect: Trapping of solar radiation in the atmosphere to maintain the temperature on earth.

→ Global Warming: General increase in average temperature on the earth.

→ Pollution: Addition of contaminants.

→ Nitrogen Fixation: Process of converting gaseous nitrogen into nitrogenous salts in soil.