So the thing that gets weird is that the heavier the particle is the more likely it is to interact with the slits themselves on the way through, in which case the wavefunction will collapse and it will seem to go through only one slit. Also, as the other person stated, even a hydrogen atom is really 4 fundamental particles that can interact with eachother. I’m not totally sure if double slit has been demonstrated with atoms but I do know it’s been done many times with electrons.
Edit: its actually totally possible to do it with much, much larger things. From wikipedia:
The experiment can be done with entities much larger than electrons and photons, although it becomes more difficult as size increases. The largest entities for which the double-slit experiment has been performed were molecules that each comprised 2000 atoms
And here’s the study that did it: https://doi.org/10.1038%2Fs41567-019-0663-9
True, but I dont want reddit’s shitty NSFW tagging system to distract from the important issue here