2. To Recall the importance of natural resources
To differentiate the atmosphere and troposphere
To explain the rain and its causes
To discuss the movement of air winds
To understand the importance of water and causes of
water pollution
To explain the biogeochemical cycles
Learning Objectives
4. Land, water and air are the important natural resources available on Earth.
Introduction
“The region of Earth where the atmosphere, hydrosphere and lithosphere interact and
support life is called biosphere.”
1 2 3
5. Atmosphere
• The mass or body of gases that
surrounds the earth or any heavenly
body is called atmosphere.
• Earth’s atmosphere extends from the
surface to a height of more than 1000
km, beyond which it merges gradually
with solar atmosphere.
• Air is a bad conductor of heat and so,
earth’s atmosphere acts as a protective
blanket.
• It keeps the average temperature of
the earth fairly steady during the day
and the whole year.
• The atmosphere prevents the sudden
increase in temperature during
daytime and also helps in retaining
heat of the earth by slowing down the
escape of heat during night.
6. Troposphere
The troposphere is the lowest major atmospheric layer, extending from the Earth's
surface up to the bottom of the stratosphere.
The troposphere is where all of Earth's weather occurs. It contains approximately 80%
of the total mass of the atmosphere.
7. Rain
Rain is liquid water in the form of droplets that have condensed from atmospheric
water vapor and then precipitated.
8. Cause of Rain
• A large amount of water
evaporates and goes into the
air during the daytime.
• Some amount of water
vapour also gets into the
atmosphere because of
various biological activities.
This air gets heated.
• The hot air rises up carrying
the water vapour with it.
• As the air rises, it expands and
cools. This cooling causes the
water vapour in the air to
condense in the form of tiny
droplets.
• This condensation of water is facilitated if some particles could act as the ‘nucleus’ for these drops to
form around.
• Once the water droplets are formed, they grow bigger by the ‘condensation’ of these water droplets.
• When the drops have grown big and heavy, they fall down in the form of rain.
9. The Movement of Air Winds
When air gets heated, it rises up and produces low pressure and cool air moves in to
take its place. The movement of air causes winds.
1
2
10. Importance of Water
• In our body, all cellular
processes take place in a water
medium.
• Substances are also transported
from one part of the body to the
other in a dissolved form.
• Hence, organisms need to
maintain the level of water
within their bodies in order to
stay alive.
• Terrestrial life-forms require
fresh water for this because
their bodies cannot tolerate or
get rid of the high amounts of
dissolved salts in saline water.
• Thus, water sources need to be
easily accessible for animals and
plants to survive on land.
11. Water Pollution
Water pollution is the contamination of water resources by human activities that
which can be harmful to life in that particular water body.
1 2
12. Mineral Riches in Soil
Soil is a very important resource. The outermost layer of our Earth is called the crust
and the minerals found in this layer supply a variety of nutrients to life-forms.
1
2
13. Mineral Riches in Soil
The factors or processes that make soil:
The huge rocks break up
into smaller pieces due to
the sun heat.
The
Sun
Water helps in the
formation of soil in two
ways. First, water could get
into the cracks in the rocks
formed due to uneven
heating by the Sun. Second,
Fast flowing water often
carries big and small
particles of rock
downstream.
Water
Strong winds erode rocks
down. The wind also carries
sand from one place to the
other like water does.
Wind
1 2 3
14. Biogeochemical Cycles
• Biogeochemical cycles are the transfer of matter and energy between the biotic and
abiotic components of the biosphere.
• The common biogeochemical cycles are
• Water cycle,
• Nitrogen cycle,
• Carbon cycle iv) Oxygen cycle
15. Oxygen Cycle
The oxygen cycle describes the movement of oxygen within and between its three
main reservoirs: the atmosphere (air), the biosphere (living things), and the lithosphere
(earth’s crust). Photosynthesis is the main driving factor of the oxygen cycle.
16. The Water Cycle
• The water cycle or the
hydrologic cycle is the
continuous movement of
water on, above, and
below the surface of the
earth.
• There are 3 states of
water that is liquid,
vapour and ice at various
places in the water cycle.
• The balance of water on
Earth remains constant
over time.
18. Summary
• The region of Earth where the atmosphere, hydrosphere and
lithosphere interact and support life is called biosphere.
• The mass or body of gases that surrounds the earth or any
heavenly body is called atmosphere.
• The troposphere is the lowest major atmospheric layer,
extending from the Earth's surface up to the bottom of the
stratosphere.
• Rain is liquid water in the form of droplets that have condensed
from atmospheric water vapour and then precipitated.
• In our body, all cellular processes take place in a water medium
• The outermost layer of our Earth is called the crust and the
minerals found in this layer supply a variety of nutrients to life-
forms.
19. Glossary
• Abiotic - Non-living chemical and physical factors of the
environment
• Bedrock - The continuous, solid rock that underlies soil and
loose sediment everywhere; an exposure of bedrock is called an
outcrop.
• Biogeochemical Cycles - The movement of chemical elements
between organisms and non-living components of the
atmosphere, aquatic systems and soils.
• Evaporation – Water converted to water vapour.
• Lithosphere - The solid outermost shell of a rocky planet.
• Precipitation – Any liquid or solid water particles that fall from
the atmosphere to the Earth’s surface
20.
21. 1. What would happen if all the oxygen present in the environment is converted to ozone?
a) We will have greater protection from UV rays of sun
b) It will become poisonous and kill living forms
c) Ozone is not stable so it will be converted back to oxygen
d) Harmful radiation from the sun will reach the earth and damage many life forms.
2. Which one of the following factors does not lead to soil formation in nature
a) Sun
b) Water
c) Wind
d) Polythene bags
3. Which of the following processes is not involved in carbon cycle?
a) Photosynthesis
b) Burning of fossil fuels
c) Transpiration
d) Respiration
22. 4. The main biological process that returns oxygen to the atmosphere is
a) Burning of fossil fuels
b) Photosynthesis
c) Respiration
d) Rainfall
5. Which of the following is not an important factor for growth of plants
a) Nutrient content of soil
b) Distance of water body from the soil
c) Amount of humus present in the soil
d) Depth of soil
6. Soil erosion can be prevented by
a) Raising forests
b) Excessive use of fertilizer
c) Deforestation
d ) Overgrazing by animals
23. 7. Rainfalls depends upon
a) The underground water table
b) The density pattern of human population in area
c) The number of water bodies in an area
d) The prevailing season in an area
8. One of the following processes is not a step involved in the water cycle operating in nature.
a) Evaporation
b) Snowfall and rain
c) Transpiration
d) Photosynthesis
9. The factor responsible for depletion of the ozone layer is
a) Excessive use of automobiles
b) Excessive use of man-made compounds containing both fluorine and chlorine
c) Excessive formation of industrial units
d) Excessive deforestation
10. Which of the following acids fall on land with rain during lightening?
a) Nitric acid and Nitrous acid
b) Hydrochloric acid and Sulphuric acid
c) Sulphuric acid and Nitrous acid
d) Hydrochloric acid and Nitrous acid
24. Answers:
1.(b) It will become poisonous and kill living forms
2. (d) Polythene bags
3. (c) Transpiration
4. (b) Rainfall
5. (a) Nutrient content of soil
6. (a) Raising forests
7. (d) The prevailing season in an area
8. (d) Photosynthesis
9. (b) Excessive use of man-made compounds containing both fluorine and chlorine
10. (b) Hydrochloric acid and Sulphuric acid
25. 1. Define Natural Resources.
2.What is Atmosphere? Explain Troposphere in detail.
3. How do rain form?
4. What are biogeochemical cycles.
5. Explain different factors which form soil.
6. Explain water cycle step-by-step.
7. What is Oxygen Cycle?
8. Explain the role of atmosphere in climate control.
9. Write a short note on Water Pollution.
10. Explain term “Evaporation”
Subjective Questions
After completing this module you will able to define natural resources, explain atmosphere and troposphere, the rain and its causes.
You will understand how air winds move, importance of water in our life, and biogeochemical cycles.
Topic List
Introduction
Atmosphere
Troposphere
Rain
Cause of Rain
The Movements of Air Winds
Importance of Water
Water Pollution
Mineral Riches in Soil
Biochemical Cycles
Oxygen Cycle
The Water Cycle
“The region of Earth where the atmosphere, hydrosphere and lithosphere interact and support life is called biosphere.”
Atmosphere
The mass or body of gases that surrounds the earth or any heavenly body is called atmosphere.
Earth’s atmosphere extends from the surface to a height of more than 1000 km, beyond which it merges gradually with solar atmosphere.
Air is a bad conductor of heat and so, earth’s atmosphere acts as a protective blanket.
It keeps the average temperature of the earth fairly steady during the day and the whole year.
The atmosphere prevents the sudden increase in temperature during daytime and also helps in retaining heat of the earth by slowing down the escape of heat during night.
Troposphere
The troposphere is the lowest major atmospheric layer, extending from the Earth's surface up to the bottom of the stratosphere. The troposphere is where all of Earth's weather occurs. It contains approximately 80% of the total mass of the atmosphere.
Rain
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated.
Cause of Rain
A large amount of water evaporates and goes into the air during the daytime.
Some amount of water vapour also gets into the atmosphere because of various biological activities. This air gets heated.
The hot air rises up carrying the water vapour with it.
As the air rises, it expands and cools. This cooling causes the water vapour in the air to condense in the form of tiny droplets.
This condensation of water is facilitated if some particles could act as the ‘nucleus’ for these drops to form around.
Once the water droplets are formed, they grow bigger by the ‘condensation’ of these water droplets.
When the drops have grown big and heavy, they fall down in the form of rain.
The Movement of Air Winds
When air gets heated, it rises up and produces low pressure and cool air moves in to take its place. The movement of air causes winds.
Importance of Water
In our body, all cellular processes take place in a water medium.
Substances are also transported from one part of the body to the other in a dissolved form.
Hence, organisms need to maintain the level of water within their bodies in order to stay alive.
Terrestrial life-forms require fresh water for this because their bodies cannot tolerate or get rid of the high amounts of dissolved salts in saline water.
Thus, water sources need to be easily accessible for animals and plants to survive on land.
Water Pollution
Water pollution is the contamination of water resources by human activities that which can be harmful to life in that particular water body.
Mineral Riches in Soil
Soil is a very important resource. Diversity of life in an area depends on the soil of that particular area. The outermost layer of our Earth is called the crust and the minerals found in this layer supply a variety of nutrients to life-forms.
The factors or processes that make soil:
• The Sun: Rocks are expanded due to sun heat during daytime. At night, these rocks cool down and contract. So all parts of the rock do not expand and contract at the same rate. This ultimately results in the formation of cracks. Thus, the huge rocks break up into smaller pieces.
• Water: Water helps in the formation of soil in two ways. First, water could get into the cracks in the rocks formed due to uneven heating by the Sun. If this water later freezes, it would cause the cracks to widen. Second, flowing water wears away even hard rock over long periods of time. Fast flowing water often carries big and small particles of rock downstream. These rocks rub against other rocks and the resultant abrasion causes the rocks to wear down into smaller and smaller particles. The water then takes these particles along with it and deposits it further down its path. Soil is thus found in places far away from its parent rock.
• Wind: In a process similar to the way in which water rubs against rocks and wears them down, strong winds also erode rocks down. The wind also carries sand from one place to the other like water does.
Biogeochemical Cycles
Biogeochemical cycles are the transfer of matter and energy between the biotic and abiotic components of the biosphere.
The common biogeochemical cycles are :- i) Water cycle, ii) Nitrogen cycle, iii) Carbon cycle iv) Oxygen cycle.
Oxygen Cycle
The oxygen cycle describes the movement of oxygen within and between its three main reservoirs: the atmosphere (air), the biosphere (living things), and the lithosphere (earth’s crust). Photosynthesis is the main driving factor of the oxygen cycle.
The Water Cycle
The water cycle or the hydrologic cycle is the continuous movement of water on, above, and below the surface of the earth.
There are 3 states of water that is liquid, vapour and ice at various places in the water cycle.
The balance of water on Earth remains constant over time.
Evaporation: The sun heats water in rivers, lakes, and the ocean and turns it into vapor or steam, which then rises into the air. Condensation: The vapor cools and turns into tiny water droplets that attach to each other and form clouds. Precipitation:. Water falls from the clouds as rain, snow, sleet, or hail. Runoff:. Some water stays on the earth’s surface and flows into rivers, lakes, reservoirs, etc. Percolation: Other water seeps down into the earth’s natural underground reservoirs called aquifers. Then the cycle begins again, as water from the earth’s surface evaporates into the air.
Let’s summarise the key-points of the chapter:
The region of Earth where the atmosphere, hydrosphere and lithosphere interact and support life is called biosphere.
The mass or body of gases that surrounds the earth or any heavenly body is called atmosphere.
The troposphere is the lowest major atmospheric layer, extending from the Earth's surface up to the bottom of the stratosphere.
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated.
In our body, all cellular processes take place in a water medium
The outermost layer of our Earth is called the crust and the minerals found in this layer supply a variety of nutrients to life-forms.
The region of Earth where the atmosphere, hydrosphere and lithosphere interact and support life is called biosphere.
The mass or body of gases that surrounds the earth or any heavenly body is called atmosphere.
The troposphere is the lowest major atmospheric layer, extending from the Earth's surface up to the bottom of the stratosphere.
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated.
In our body, all cellular processes take place in a water medium
The outermost layer of our Earth is called the crust and the minerals found in this layer supply a variety of nutrients to life-forms.