⛪Home⇐ Class IX Natural Resources


Mind Maps
 
IX_SCI_Natural_Resources/
IX_SCI_Natural_Resources/
 
 


Class IX - science: Natural Resources
One Word Answer Questions:
Q) What is the outer crust of the earth?
A)  

Q) What Contains mixture of small particles of rock?
    
A)  

Q) What is the mixture of many gases like nitrogen, oxygen, carbon dioxide and water vapour?
A)  

Q) Which plants convert carbon dioxide into glucose in the presence of Sunlight?
A)  

Q) What is formed due to the heating of water bodies and the activities of living organisms?
A)  

Q) Things Composed of Non - Living things are called what type of resources?
A)  

Q) Obtained from biosphere and have life are called what type of resources?
A)  

Q) Give an example of abiotic resource?
A)  

Q) Give an example of biotic resource?
A)  

Q) Ozone Layer is denoted as?
A)  

Q) Which is an abundant element on our Earth?
A)  

Q) Give an example of water pollution?
A)  

Q) Where do we find most of the water on Earth's surface?
A)  

Short Answer Questions:
Q) Explain about the Water pollution?
A)

Q) Explain about the Air pollution?
A)

Q) Explain about Water-Cycle?
A)

Q) Explain about Nitrogen-Cycle?
A)

Q) Explain about the Green house effect??
A)

Q) What is the importance of nitrogen?
A)

Q) What is air pollution?
A)

Q) Write a short note on Ozone Layer?
A)

Q) What is nitrogen-fixing bacteria?
A)

Q) Mention the main sources of Carbondioxide?
A)

Q) Explain the physical process of fixing atmospheric nitrogen?
A)

Q) Write a short note on Carbon-Cycle?
A)

Long Answer Questions:
Q) What are the factors which lead to the formation of wind?
A)

Q) Explain about the nitrogen and oxygen cycle?
A)

Q) Explain about the carbon and water cycle with neat diagrams?
A)

Q) What is Green house effect and explain about ozone layer?
A)

Q) Explain about the water, soil and air pollution?
A)

Q) How water is polluted?
A)

Q) Explain about the resources on the Earth in detail?
A)

Q) Explain the availability and existence of water?
A)

Q) What is air pollution and what are the causes and effects of air pollution?
A)

Q) Explain the Role Of The Atmosphere In Climate Control?
A)



Introduction

The resources available on the Earth and the energy from the Sun are necessary to meet the basic requirements of all life-forms on the Earth.

What are these resources on the Earth?

These are the land, the water and the air. The outer crust of the Earth is called the lithosphere. Water covers 75% of the Earth's surface. It is also found underground. These comprise the hydrosphere. The air that covers the whole of the Earth like a blanket, is called the atmosphere. Living things are found where these three exist.
Living things constitute the biotic component of the biosphere. The air, the water and the soil form the non-living or abiotic component of the biosphere.

Natural Resources
The Breath of Life: Air

It is a mixture of many gases like nitrogen, oxygen, carbon dioxide and water vapour.Eukaryotic cells and many prokaryotic cells,need oxygen to break down glucose molecules and get energy for their activities.This results in the production of carbon dioxide.
The percentage of carbon dioxide in our atmosphere is a mere fraction of a percent because carbon dioxide is 'fixed' in two ways.

  • Green plants convert carbon dioxide into glucose in the presence of Sunlight.
  • Many marine animals use carbonates dissolved in sea-water to make their shells.
Natural Resources
The Role Of The Atmosphere In Climate Control

The atmosphere keeps the average temperature of the Earth fairly steady during the day and even during the course of the whole year. The atmosphere prevents the sudden increase in temperature during the daylight hours. And during the night, it slows down the escape of heat into outer space.

The Movement Of Air: Winds

We have all felt the relief brought by cool evening breezes after a hot day. And sometimes, we are lucky enough to get rains after some days of really hot weather.
These phenomena are the result of changes that take place in our atmosphere due to the heating of air and the formation of water vapour. Water vapour is formed due to the heating of air and the formation of water vapour. The air above the land gets heated faster and starts rising. The movements of air from one region to the other create winds. During the day, the direction of the wind would be from the sea to the land.
At night, both land and sea start to cool.

Activity:

Place a candle in a beaker or widemouthed bottle and light it. Light an incense stick and take it to the mouth of the above bottle.
The patterns revealed by the smoke show us the directions in which hot and cold air move. In a similar manner, when air is heated by radiation from the heated land or water, it rises. But land gets heated faster than water.

Natural Resources
Rain

When water bodies are heated during the day, a large amount of water evaporates and goes into the air. Some amount of water vapour also get into the atmosphere because of various biological activities. This air also 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. Normally dust and other suspended particles in the air perform this function.

Air Pollution

The fossil fuels like coal and petroleum contain small amounts of nitrogen and sulphur. When these fuels are burnt,nitrogen and sulphur too are burnt and this produces different oxides of nitrogen and sulphur.
Not only is the inhalation of these gases dangerous,they also dissolve in rain to give rise to acid rain. The combustion of fossil fuels also increases the amount of suspended particles in air.

These suspended particles could be unburnt carbon particles or substances called hydrocarbons. Presence of high levels of all these pollutants cause visibility to be lowered,especially in cold weather when water also condenses out of air. This is known as smog and is a visible indication of air pollution.
An increase in the content of these harmful substances in air is called air pollution.

Natural Resources Natural Resources
Water

Water is one of the major resources which determine life on land.
Water occupies a very large area of the Earth's surface and is also found underground. Some amount of water exists in the form of water vapour in the atmosphere. Most of the water on Earth's surface is found in seas and oceans and is saline.
Fresh water is found frozen in the ice-caps at the two poles and on snow-covered mountains. The underground water and the water in rivers,lakes and ponds is also fresh.

The availability of water decides not only the number of individuals of each species that are able to survive in a particular area, but it also decides the diversity of life there.
Other factors like the temperature and nature of soil also matter.

Water Pollution

Water dissolves the fertilizers and pesticides that we use on our farms. Some substances are washed into the water bodies. Sewage from our towns and cities and the waste from factories are also dumped into rivers or lakes.

All this can affect the life-forms that are found in these water bodies in various ways. It can encourage the growth of some life-forms and harm some other life-forms. This affects the balance between various organisms which had been established in that system.

Natural Resources Natural Resources
Soil

Soil is a mixture. It contains small particles of rock (of different sizes). It also contains bits of decayed living organisms which is called humus.In addition, soil also contains various forms of microscopic life.
Humus is a major factor in deciding the soil structure because it causes the soil to become more porous and allows water and air to penetrate deep underground.The topmost layer of the soil that contains humus and living organisms in addition to the soil particles is called the topsoil.
Removal of useful components from the soil and addition of other substances,which adversely affect the fertility of the soil and kill the diversity of organisms that live in it is called soil pollution.

Natural Resources Natural Resources
Water-Cycle

The water evaporates from the water bodies and subsequent condensation of this water vapour leads to rain.The whole process in which water evaporates and falls on the land as rain and later flows back into the sea via rivers is known as the water-cycle.

All of the water that falls on the land does not immediately flow back into the sea. Some of it seeps into the soil and becomes part of the underground reservoir of fresh-water.

Natural Resources
Nitrogen-Cycle

There is a nitrogen-cycle in nature in which nitrogen passes from its elemental form in the atmosphere into simple molecules in the soil and water,which get converted to more complex molecules in living beings and back again to the simple nitrogen molecule in the atmosphere.

Nitrogen gas makes up 78 of our atmosphere and nitrogen is also a part of many molecules essential to life like proteins,nucleic acids (DNA and RNA) and some vitamins.Nitrogen is found in other biologically important compounds such as alkaloids and urea too.

The nitrogen-fixing bacteria are found in the roots of legumes in special structures called root nodules. Other than these bacteria,the only other manner in which the nitrogen molecule is converted to nitrates and nitrites is by a physical process.During lightning,the high temperatures and pressures created in the air convert nitrogen into oxides of nitrogen.

Natural Resources
Carbon-Cycle
  • It occurs in the elemental form as diamonds and graphite. In the combined state, it is found as carbon dioxide in the atmosphere, as carbonate and hydrogencarbonate salts in various mineral.
  • The endoskeletons and exoskeletons of various animals are also formed from carbonate salts.
  • Carbondioxide is used during photosynthesis, during respiration, of the living things, it is given out.
  • Another process that adds to the carbon dioxide in the atmosphere is the process of combustion where fuels are burnt to provide energy for various needs like heating, cooking, transportation and industrial processes.

Green house effect: Carbon dioxide is one of the greenhouse gases. An increase in the carbon dioxide content in the atmosphere would cause more heat to be retained by the atmosphere and lead to global warming.

Natural Resources
Natural Resources
Oxygen-Cycle

Oxygen from the atmosphere is used up in three processes, namely combustion, respiration and in the formation of oxides of nitrogen. Oxygen is returned to the atmosphere in only one major process, that is, photosynthesis.

Natural Resources Natural Resources
Ozone Layer

It absorbs harmful radiations from the Sun. This prevents those harmful radiations from reaching the surface of the Earth where they may damage many forms of life. It is denoted as O3.
Various man-made compounds like CFCs carbon compounds having both fluorine and chlorine, resulted in reduction of ozone layer.

Natural Resources
- Facebook | - Twitter | - Google+ | - YouTube | - Mail
Meritpath...Way to Success!

Meritpath provides well organized smart e-learning study material with balanced passive and participatory teaching methodology. Meritpath is on-line e-learning education portal with dynamic interactive hands on sessions and worksheets.