CH 7 OUR COUNTRY – INDIA

The properties of air are: Air is a mixture of many gases, water vapours and dust particles. Air exerts pressure. Air has mass. Air occupies space. Air is colourless and odourless.

We all need air to survive. Air contains oxygen and carbon dioxide useful to plants and animals. Plants use carbon dioxide of the air to make their own food by a process called photosynthesis.

Most living things need oxygen to survive. Oxygen helps organisms grow, reproduce, and turn food into energy. Humans get the oxygen they need by breathing through their nose and mouth into their lungs. Oxygen gives our cells the ability to break down food in order to get the energy we need to survive.v

Answer. Answer: Hot air, cold air and dry air.

There are four categories for air masses: arctic, tropical, polar and equatorial. Arctic air masses form in the Arctic region and are very cold.

Pure air contains around 78% nitrogen, 21% oxygen, and 0.03% carbon dioxide also small amounts of argon, methane, ozone, and water vapours. Smog is not present.

NitrogenThe mixture of gases that makes up the Earth’s atmosphere is known as air. Nitrogen makes up 78 % of this gas, which is mixed with oxygen (21%), water vapour (variable), argon (0.9 %), carbon dioxide (0.04%), and trace gases.

Air is important for living things. People need to breathe, and so do lots of other animals—and plants! Breathing is part of a process called respiration. During respiration, a living thing takes in oxygen from the air and gives out carbon dioxide.

The name Air is primarily a gender-neutral name of English origin that means Gaseous Substance Surrounding The Earth. Also a musical term meaning a melody or aria.

Air include oxygen , Nitrogen etc. In our atmosphere There is 78% Nitrogen,. 21 % Oxygen and 1% other gases which include methane , CO2 etc.