Composition of Earth's atmosphere | |||
---|---|---|---|
Gases having fairly uniform concentrations |
Percent by volume | Gases having variable concentrations | Percent by volume |
Nitrogen, N2 | 78 | Water vapor, H20 | 0 to 4 |
Oxygen, O2 | 21 | Carbon dioxide, CO2 | 0.034 |
Argon, Ar | 0.9 | Ozone, O3 | 0.000004* |
Neon, Ne | 0.0018 | Carbon monoxide, CO | 0.00002* |
Helium, He | 0.0005 | Sulfur dioxide, SO2 | 0.000001* |
Methane, CH4 | 0.0001 | Nitrogen dioxide, NO2 | 0.000001* |
Hydrogen, H2 | 0.000005 | Particles(dust, pollen) | 0.00001* |
* Average value in polluted air. |
Life on Earth would not be possible without air. We need oxygen from the air to breathe. Plants need carbon dioxide from the air to prepare food through photosynthesis. Humans get energy due to the combustion of food inside the body, which is supported by air.
Composition of air:
Air contains mostly nitrogen and oxygen, and small
amounts of argon, carbon dioxide and water vapor.
Other gases namely hydrogen, methane, nitrogen dioxide,
ozone, helium, neon, krypton, xenon, carbon monoxide and
sulfur dioxide are present in traces. The percentage
of all these components also varies, but only
slightly, from one location to another. The
average composition of air by volume is given in the table.
Function of air:
Air Pollution:
An undesirable change in the physical,
chemical or biological characteristics of air is
called air pollution. Any material in the atmosphere
that is harmful to health is defined as an air pollutant.
The pollution of air may be caused by natural processes
or by human activities.
Effects of air pollution:
Prevention of air pollution:
Some of the steps you can take as an individual or
a group of individuals to improve upon the air quality
around you are as follows: