How does water stored in a mud pot remain cool?                  38
Why does water appear white in a waterfall though
it is colourless?                                                39
How is quantity of water in dams and reservoirs measured?        40
How do wells in the beach yield good drinking water?             41
Is rain water hundred per cent pure?
Can we use it as drinking water?                                 42
Why do water drops dance when poured on a hot plate?             43
Is there a simple way to check the purity and genuineness
of mineral water available in the market?                        43
Why are water drops spherical?                                   45