Composition of air
The air in Earth's atmosphere is
made up of approximately 78
percent nitrogen and 21 percent
oxygen. Air also has small amounts
of other gases, too, such as carbon
dioxide, neon, and hydrogen.
Composition of air
and air pollution
Air pollution
Air pollution is contamination of
the indoor or outdoor
environment by any chemical,
physical or biological agent that
modifies the natural
characteristics of the
atmosphere.
Common air
pollutants
Ozone (O3)
Nitrogen dioxide
(NO2) Carbon
monoxide (CO)
Sulphur dioxide
(SO2)
Acid rain is formed when sulphur
dioxide (SO2) and nitrogen dioxide
(NO2) react in the atmosphere with
water, oxygen and other chemicals
to form various acidic compounds.
These compounds are transported in
the air by the wind, until they fall to
the ground in either wet or dry
form.