Page 136 - Health, Population and Environment Education 9

viii. Study and research
Various studies and researches related to the nature/ environment are done in natural
environment. Studies and researches about different animals, plants and other aspects of
nature are conducted in natural environment. Various geographical studies and studies
of science are based on the different natural phenomena that happen in the natural
environment. Nature in this sense is like a big lab where various geographical and
scientific researches and experiments are carried out to find out the facts.
Activity: 2

Write some of the natural resources found in your surrounding and briefly describe
how you have been utilizing them.

Status of various types of natural resources

There is an intricate relation between the nature and human beings. Human beings
depend on the nature or resources available in nature for various things. Similarly, the
conservation of nature also depends on planned decisions and actions of human beings.
In this lesson, we will see the situation of various types of resources.

Air
The invisible mixture of various gases present in the atmosphere that surrounds the earth
is called air. The space above the land mass and water bodies on the earth is the layer of
air which is called atmosphere. It is composed of various gases, water vapour and dust
particles. Atmosphere contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon
dioxide and 0.0045 other gases. Carbon dioxide is the heaviest gas whereas nitrogen and
hydrogen are light gases. The gases like neon, helium, ozone are comparatively lighter
than the dust particles and water vapour present in air. When the water bodies are heated
the water changes into water vapour which mixes in the air in the form of gas.

Importance of air

i. Respiration
The main importance of air is for respiration. All living creatures including human beings
need air for respiration. We inhale oxygen and exhale carbon dioxide in the process of
respiration.

ii. Energy generation
Moving air which is called wind is very useful for
generating energy. We can generate wind energy from air.
Electricity can be generated by using wind mills.

Fig: 5
136 GREEN Environment Population and Health Education Book-9