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Name: John F.
Status: other
Age: 50s
Location: N/A
Country: N/A
Date: 2001 - 2002

Hello. I would like to know how fast an electron moves when it changes transition states from ground state to a great distance, then back to its ground state in its orbital. Does it move at the speed of light or is the transition truly instantaneous? And if is instantaneous, then how is this violation of the relativistic speed limit accounted for? And if the transition takes a finite time, where is the electron during its transition? Does it just disappear and reappear?

When an electron changes from its ground state to a higher-energy state, it does not necessarily have to instantaneously change its position. Electron orbitals are mathematically described as probability densities. All orbitals (except for 1s) have specific two-dimensional regions of zero probability (nodes), but otherwise the probability being at any distance from the nucleus is finite. In other words, no matter what energy state an electron is in, it's possible for it to be any distance from the nucleus.

When an electron changes its level, what changes is its energy (and possibly things like angular momentum and spin as well). This affects its most probable distance from the nucleus, but it does not specify a particular separation between the nucleus and electron. So your question of how the electron instantly changes its position is moot, because it does not instantly change its position.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

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