Air is the invisible mixture of gases that surrounds the Earth. Air contains important substances, such as oxygen and nitrogen, that most species need to survive. Human beings, of course, are one of those species. Sometimes, the word “atmosphere” is used instead of the word “air.”
CH 4 AIR
the mixture of gases that surrounds the earth and that people, animals and plants breathe.
There is no air on the moon and therefore no air pressure.
Insolation is the incoming solar energy intercepted by the earth.
The degree of hotness and coldness of the air is known as temperature.
It protects us from the harmful effect of the sunrays.
Stratosphere contains a layer of ozone gas.
Green plants use carbon dioxide to make their food and release oxygen.
It has tendency to go down.
When air is heated, it expands, becomes lighter and goes up.