describe an activity to show that the particles are very small using the following materials - 4beakers, spatula, 4 test tubes, distilled water and few crystals of potassium permagnate.
Requirements: Test tubes three-fourth filled with water, a dropper, small crystals of potassium permanganate.
Procedure: In test tube no. 1, drop one small crystal of KMnO4. Then cover the mouth of the test tube with thumb and shake the test tube vigorously. Then with the help of a dropper take out a few drops of solution from it and pour into test tube no. 2 and shake its contents vigorously. Observe the colour of the solution. Repeat this procedure for test tube no. 3 and 4. Then pour the drops from test tube no.5 into beaker half filled with water and observe the colour change.
Observation: One will notice that the colour of solution in test tube no.1 is deep pink. However, the colour of the solution becomes less and less pink in test tube no.2 to 4, till in the beaker the pink colour is hardly visible.
Conclusion: The colour of potassium permanganate fades on dilution with water because the particles of potassium permanganate decrease gradually from test tube no.1 to 4.
Hence one can conclude that the particles of matter are very, very small. They are so small that they are not visible to the unaided eye.