Name three different types of evidence for the existence

Solution 1CQ

1. Small particles move in still water in random motion. The first evidence for this was given by Robert Brown as he observed the movement of pollen grains in still water. This random motion of tiny particles in the fluid is possible because of the thermal motions of the fluid molecules which collides with the particles which are floating on it. This evidence led to the fact that the fluid is made up of basic fundamental units