If it were possible to stand on the surface of a nucleus, the location of electrons would be described by their probability distributions rather than fixed positions. According to the principles of quantum mechanics, electrons do not have definite positions until they are measured or observed. Instead, their behavior is described by wavefunctions that give the probability of finding the electron at different locations.
In the case of an atom, the probability distribution of electrons is typically represented by atomic orbitals. These orbitals describe regions of high probability density where an electron is likely to be found. However, it is important to note that even within these orbitals, the exact position of an electron cannot be determined precisely.
When a measurement or observation is made to determine the position or other properties of an electron, the wavefunction describing its probability distribution collapses into a specific state. This is often referred to as the collapse of the wavefunction or wavefunction collapse.
If you were constantly "measuring" the position of an electron while standing on the nucleus, it would indeed cause frequent collapses of the electron's wavefunction. However, the specifics of continuous measurement on such a small scale are still subjects of ongoing research and debate in the field of quantum mechanics.
It's worth noting that the act of measurement typically involves interacting with the electron, which can disturb its state. The uncertainty principle in quantum mechanics states that there is a fundamental limit to the precision with which certain pairs of physical properties, such as position and momentum, can be simultaneously known. This inherent uncertainty is a fundamental aspect of the quantum nature of particles, including electrons.
In summary, if it were possible to stand on the surface of a nucleus, the location of electrons would be described by probability distributions rather than fixed positions. Continuous measurement or observation would indeed cause frequent collapses of the electron's wavefunction, but the details of such continuous measurement and its effects on the quantum state are still active areas of research.