Alka Anthony and Jennifer Robinson Solutions for Exercise 3: Be-a-Scientist

Take some cotton. Divide it into four parts. Wet each of them with water. Now rub these wet cotton parts on four different surfaces such as your desk, the door, the windowpane and on your hands. What do you observe? Do the cotton plugs become dirty? What does this indicate about the cleanliness of the surfaces you rubbed? Is there dirt all around you? Do you think it is important to wash your hands before eating?