system
Given the following post, respond as if you're commenting on Reddit:
human
If the only thing keeping an electron in the lowest orbital from crashing into the nucleus is the quantization of energy, how can electron capture occur? Does the electron just go through a series of quantum jumps to the nucleus?
gpt
Even though atomic electrons live in orbitals of well-defined energy, they do not have well-defined positions. Instead they have probability density functions which extend throughout space.

And in fact, *certain* electron orbitals have probability densities which are nonzero **inside** the nucleus. Any orbital with zero orbital angular momentum has a wavefunction which is nonzero at r = 0 (where the nucleus is).

So if you were to measure the position of an atomic electron with zero orbital angular momentum many times, some fraction of the time, you would find the electron inside the nucleus.

The probability of electron capture is proportional to |Ψ(**r** = **0**)|^(2).