NCERT 9TH CLASS SCIENCE CHAPTER NATURAL RESOURCES

INTRODUCTION


 The materials present in natural environment and useful to living organisms are called natural resources.
 A resource satisfies human wants. Water, air, sunshine, land, soil, forests, wildlife, fishes, minerals and power resources all are useful to man. All basic needs of food, 

shelter and clothing are supplied by natural resources on earth. Natural resource includes total natural environment,

that is the entire surface layer of earth, because all parts of earth's surface are of some use to man in they contribute to the production of necessities and comforts of mankind.
The word resource is use for "means of supplying a material generally held in reserve".
    

Natural Resources

    Substances used by man in bulk for survival are called resources and since they are found in nature, they are called natural resources.
    The resources available on earth include land [Lithosphere], water [Hydrosphere] and Air [Atmosphere].

  •  Probably, the earth is the only planet on which life exists. 
  •  Life exists on earth because it has all the physical conditions necessary for sustaining it. An ambient temperature, water and food are the basic need of all life forms.
  • These basic needs of the life  forms are to be met by the resources available on the earth and the energy from the sun.
  • The outer crust of the earth is called lithosphere.
  • The water present on the earth's surface and underground constitute hydrosphere.
  • The air that covers the whole of the earth like a blanket is called atmosphere.
  •  About 75% of the earth's surface is covered with water.
  • The life sustaining zone of the earth where the lithosphere, the hydrosphere and the atmosphere interact and make life possible is called the biosphere.

                    

Differences between inexhaustible and exhaustible resources

        Inexhaustible                            Exhaustible
    1.   These resources have no chance        1.    These resources have every chance of 
          of getting exhausted.                                    getting exhausted.
    2. &nbs
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