The claim I read is that it is due to the mass of the molecules being different. The masses being larger should result in them moving slower I think? (At the s

The claim I read is that it is due to the mass of the molecules being different. The masses being larger should result in them moving slower I think? (At the same temperature) Allegedly this influences how the diffusion/osmosis works out, resulting in more or less water in the cells on the tongue or something? It is also possible that I am getting things mixed up with when he tasted extremely pure water, which iirc causes some cells to burst, causing a sweet taste?