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SAI INTERNATIONAL SCHOOL
                                                        Class-7

                                                      Mind map
                                                  Subject-Physics
                                      Ch.- Water: The Life-giving Liquid

                              Subtopic- Sources of Water & Types of Water










                  Sources of                  Types of                       Types of

                     Water                      Water                       Hardness





                       1. Rainwater                1. Hard Water
                                                                                   1. Temporary Hardness
                        2. Surface              (Water that doesn't
                           water                 lather readily with            (It is caused by the presence
                                                        soap)                    of bicarbonates of Calcium
                        3. Ground                                                   and Magnesium salts)
                           water





                                                   2. Soft Water
                                                                                     2. Permanent Hardness
                                                (Water that readily
                                                lathers with soap)              (It is caused by the presence of
                                                                                   chlorides and sulphates of
                                                                                    calcium and magnesium)
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