This is not a SFW instance. NSFW communities will be tagged, and efforts will be made to keep SFW communities clean, but proceed at your own comfort level.
It is because of the hydrogen, but it’s not really to do with the mass, but rather because a “collision”/interaction is much more likely. For instance, 58Ni has the same likelihood to interact as hydrogen, while deuterium has only a fifth. 135Xe meanwhile has some millions of times the absorption power of hydrogen and it’s quite a lot heavier. It’s just not very practical as an absorber.
It is because of the hydrogen, but it’s not really to do with the mass, but rather because a “collision”/interaction is much more likely. For instance, 58Ni has the same likelihood to interact as hydrogen, while deuterium has only a fifth. 135Xe meanwhile has some millions of times the absorption power of hydrogen and it’s quite a lot heavier. It’s just not very practical as an absorber.