After the completion
of this lesson, students will be able to:
* know about the
occurence and composition of oxygen, nitrogen and carbon dioxide in the
* understand the
properties and uses of oxygen, nitrogen and carbon dioxide.
* understand nitrogen
* identify the causes
of green house effect, global warming and acid rain.
* suggest remedial measures
for the prevention and control of these effects.
Air is a mixture of gases that
surrounds our planet earth. It is essential for the survival of all the living
things. Air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon
dioxide and small amount of other gases. We breathe in oxygen and breathe out
carbon dioxide. Plants in turn use carbon dioxde for photosynthesis and release
oxygen into the atmosphere. Since men have been cutting down trees for their
needs, the amount of carbon dioxide in the atmosphere is increasing. This is
responsible for the raising of atmospheric temperature. Industries and vehicles
release gases like carbon monoxide and sulphur dioxide into the atmosphere.
This has resulted in effects like global warming and acid rain which affect us
in many ways. In total, the quality of air is gone in the modern days. In this
lesson we are going to study about the effects like green house effect, global
warming and acid rain. We will also study about occurrence and properties of
the gases oxygen, nitrogen and carbon dioxide.