Question

Name two prominent phenomena which provide conclusive evidence of molecular motion.

Answer 1

1. diffusion of gases : diffusion of gas is the most prominent phenomenon. as you know, gases have tendency to diffuse with other gases. actually this happens because of molecular motion of gases. kinetic energy of different gases are different. lower the molecular mass, higher will be tendency to diffuse. that's why when two gases come in contact they start to diffuse but the the gas of lighter molecules diffuse more faster than that of heavier molecules.
2. evaporation : evaporation occurs on the surface of liquid. it happens when atoms or molecules escape from the liquid and turn into vapor. This is also a good prominent phenomena which provides conclusive evidence of molecular motion.

Answer 2

Answer:

diffusion and Brownian motion