Once again, no energy is needed for this task. Its main difference from diffusion is that osmosis deals only with the diffusion of water or fluid, while diffusion is open to any molecule. In the laboratory two weeks ago, in the part relating to osmosis, it was clear that osmosis had occurred within the environment because the 'cell' had gained weight, demonstrating how the particles tend to pass from a high concentration at a low concentration. The initial weight of the “cell” was 18.6 grams and after the hour of incubation the final weight of the cell was 21.9 grams. Hypotonic tonicity highlighted the diffusion of water inside the cell where its concentration was lower than that of water