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Coal and petroleum are valuable natural resources. If
                                                    we keep on using them at the rate we are doing today,

                                                    they will not survive very long. They are limited and
                                                    non-renewable.  So,  the  use  of  coal  and  petroleum

                                                    should be limited. Try to save them for future also.
                                                    So, it is necessary to search and develop renewable

                            Solar Cooker            sources of energy. The energy sources which can be
                                                    replenished  and  can  be  used  again  and  again  are
                                                    called renewable sources of energy. Some renewable

                                                    sources of energy are solar energy              , wind energy     , tidal
                                                    energy and      geothermal energy.

                                                    These can never get exhausted. Windmills                     use wind
                                                    energy  to  run.  We  can  use  windmills  to  generate
                                                    electricity and for lifting water from wells. Wind energy
                              Windmill              is pollution less and a renewable source of energy.

                           Fact FileFact FileFact FileFact FileFact File
                           Fact FileFact FileFact FileFact FileFact File
                           Fact File
                           Fact File
                              w  The feldspars make up more than 50% of the Earth's crust.
                              w  The Ruby is one of the most popular gemstone today.


                     Scientific Terms

                     Blast furnace  :  a metallurgical furnace used for producing metals
                     Geologists        :  a scientist who studies the constituents of the Earth's crust
                     Ore               :  a mineral from which a metal can be extracted at a profit
                     Vent              :  mouth of a volcano
                     Volcano           :  a place on the Earth's crust through which molten rock slopes down



                     Chapter at a Glance
                     ³  Sedimentary rocks are formed by sediments of small pieces of rocks. Conglomerate,
                           sandstone, coal, limestone and shale are sedimentary rocks.
                     ³  Three types of rocks are igneous, sedimentary and metamorphic.
                     ³  Rocks are made up of minerals.
                     ³  Metamorphic  rocks  are  the  transformed  igneous  and  sedimentary  rocks.  Slate,
                           marble, quartzite and gneiss are metamorphic rocks.
                     ³  Igneous rocks are formed by cooling of magma. Granite, pumice and basalt are
                           igneous rocks.
                     ³  Some renewable sources of energy are solar energy, wind energy, geothermal energy
                           ,tidal energy etc.
                     ³  In India, petroleum is found in Digboi, Bombay high, LB Charla (West Godavari) and
                           Ankaleswar.



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