2nd Class Science Our Environment

Our Environment

Category : 2nd Class

OUR ENVIRONMENT

 

 

FUNDAMENTAL

  • Environment includes everything, i.e. vegetation, water, microorganisms, soil, rocks, atmosphere, etc.
  • Our environment consists of both living and non-living things.eg. Atmosphere, sea, river, lakes, soil etc.
  • Atmosphere means the sphere of air surrounding the earth. Mainly, there are four sub- systems called spheres, they are land (lithosphere), water (hydrosphere), living things (biosphere) and air (atmosphere).
  • The atmosphere consists of four unique layers:

The troposphere       (0-8 miles)

The stratosphere       (8-30 miles)

The mesosphere       (30-50 miles)                                  

The thermosphere    (50-120 miles)                                 

  • Atmosphere protects the life on the earth. Atmosphere has gases like nitrogen hydrogen, carbon dioxide, argon, helium and some more gases. It has 78% nitrogen, 21% oxygen and 1% other gases.                            
  • Oxygen is the most important gas of atmosphere, as most of the living organisms inhale it.
  • Seas are the natural source of water.                               
  • Rivers are natural source of water. It is usually freshwater, flowing towards an etc. e.g. Ganges, Yamuna.                               
  • Lakes are both natural and man-made. A lake is a still water body surrounded by from all sides. Lakes are a body of fresh or salt water of considerable size surrounded by land. E.g. Dal Lake, Wular Lake Etc.
  • Soil is a natural resource made up of tiny particles of broken rock, mineral, clay and humus. Soil is an important ingredient for the survival of living organisms on earth.
  • There are mainly three types of soil-sandy soil, clayey soil and loamy soil.
  • Hard surface of the earth consists of rocks. The earth is made up of hard matter called rocks. They are many shapes, Sizes and colour.
  • Various kinds of rocks are

(i) Granite \[\to \]It is used for making buildings and statutes

(ii) Marble \[\to \] It is used for making building and statutes

(iii) Sandstone\[\to \] These rocks are soft in nature.

                        Coal, slate, graphite, chalk is also soft.

Other Topics

Notes - Our Environment
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