Page 100 - ICSE Chemistry 6

5 Air and Atmosphere

Learning Outcomes Key Concepts
Students will be able to
• Air: A Mixture of Gases
• describe diff erent components of air and their composi on.
• state the importance of air for sustenance of life and for other physical • Uses of Components of
and chemical processes. Air
• Importance of Air
• describe the uses of oxygen and nitrogen.
• Maintenance of Air
• discuss the causes of increase of carbon dioxide into the atmosphere.
Composition in Nature
• Air Pollution
• Atmosphere

Warm Up Activity
• Can you see air? _________________

• Can you feel air? _________________

• List three things for which you feel air is necessary.
_________________ _________________ _________________

Air is present all around us. Have you ever seen it? No, you cannot see air but you feel its presence when
it blows. The presence of air can also be felt when curtains move, leaves rustle and clothes hanging on a
clothes line sway due to moving air.

Air is a mixture of diff erent gases that forms the atmosphere Thirst for Knowledge
giving life to plants and animals. The layer of air that surrounds
the earth is called atmosphere. The sustenance of life is due to a The earth’s atmosphere extends
combina on of gases that collec vely form the atmosphere. approximately up to 480 km. It is
thickest up to the height of 16 km,
As we go higher, the atmosphere becomes thinner and slowly where clouds are present.
fades into vacuum.

AIR: A MIXTURE OF GASES

Un l the 18th century, it was believed that air is one substance. Later on, various experiments concluded
that air is a mixture of gases. It was in 1789 that Antoine Lavoisier, a French chemist, proved that air

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