How much pressure can a single atom sustain before it collapses?

  • $\begingroup$ By "breaking apart" you mean (fully) ionizing? It'll probably depend strongly on the other atoms you're pressing this one against, and I guess something like adsorption is more likely than ionization. $\endgroup$
    – stafusa
    Sep 16, 2017 at 10:59
  • $\begingroup$ @stafusa I mean breaking it into protons, neurons and electrons. i thought ionization only refers to the loss\addition of electrons – $\endgroup$ Sep 16, 2017 at 11:14
  • $\begingroup$ OK, so you mean fully ionizing it, in the sense of popping all the electrons out of it, plus fissioning the nucleus. If you compress it that strongly against other atoms (like in a particle accelerator or in a star), you'll end up with nuclear fusion. $\endgroup$
    – stafusa
    Sep 16, 2017 at 11:19
  • $\begingroup$ @stafusa How strongly should it be compressed in order for that to happen? (I will change my question to refer to pressure rather than weight so you could reply in a form of an Answer, because this was exactly what i wanted to ask.) $\endgroup$ Sep 16, 2017 at 11:24
  • 2
    $\begingroup$ nuclear fusion is (wiki) " is a reaction in which two or more atomic nuclei ..." and the question says " a single atom" ¿? $\endgroup$ Sep 16, 2017 at 11:43

1 Answer 1


Huge, probably of order $10^{34}$Pa.

One cannot have nuclear fusion with a single atom, because fusion is a process between different nuclei. If we're talking about at least two atoms being squeezed together, than a very rough estimate gives $10^{28}$Pa for fusion at low temperatures. Of course the actual values would also depend on what elements are involved. One can check Wikipedia for more details.

If we're talking about the collapse of a single atom into a tiny neutron star, then the pressure needed is much higher, $\sim10^{34}$Pa (check also Hebeler et al. (2013)).


Not the answer you're looking for? Browse other questions tagged or ask your own question.