List the evidence you know of the existence of molecules.

An example of the existence of molecules can be a phenomenon called diffusion in physics. Diffusion is the process of mutual penetration of molecules of one substance between the molecules of another. For example, if we open the lid of a bottle with a female perfume, the molecules of the perfume begin to mix with the molecules of the air, and after a while we begin to smell the perfume. Other examples of diffusion are salting vegetables, brewing tea, etc.

Another proof of the existence of molecules is Brownian motion.