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Do electrons in an atom revolve around the the nucleus clockwise or counterclockwise?

Is there any rule to determine?

Mithoron
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    No. Electrons don't revolve around anything at all. You have a choice of two inappropriately-termed words to describe the electronic state you're interested in: spin up and spin down. Neither term refers to spin in any sense of the word, not to mention up or down, which are even less appropriate. In short: electrons have a property called spin which can have values of up or down (more confusingly notated as 1/2 or -1/2). – Todd Minehardt Nov 02 '16 at 04:06
  • What would be the spin dependence of time? – Another.Chemist Nov 02 '16 at 04:57
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    Come to think of it, even ordinary things in 3D do not rotate clockwise or counterclockwise. (Also, electrons are not ordinary things, and they do not rotate at all.) – Ivan Neretin Nov 02 '16 at 05:39
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    Even in an orbital the electrons in an atom so not rotate, they just have a probability of being at some position. The spin of an electrons as mentioned above does not literally mean that they 'spin' but rather that they have a property that obeys equations describing angular momentum. Yes it is all very odd compared to everyday experience, but its what experiments teach us. – porphyrin Nov 02 '16 at 09:38
  • http://chemistry.stackexchange.com/questions/36987/does-the-shared-electron-in-covalent-bonds-revolve-around-nucleus – Mithoron Dec 11 '16 at 00:20

1 Answers1

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Lets make this clear:

  1. Electron is elementary particle.

  2. Like other particles it can be also described as wave (wave–particle duality).

  3. It may be a point particle, but it possibly has finite, but very small radius.

  4. Electrons do move around nuclei. Corpuscular nature of electron completely excludes the possibility that electrons in atoms don't move. They also may or may not have true orbits depending on which interpretation of quantum mechanics is really "true". So, they move and are very fast; their velocities can be even relativistic (see this answer) and in such cases even Schrödinger equation doesn't describe atoms properly.

As Ivan pointed out in comments, orbits of electrons in atom, which wasn't disturbed in any way, can't be seen, which is true for any system (observer effect). Still even single electron during ionisation of an atom was observed using attosecond laser; a film of movement of electron cloud was created (see also).

As for OP's question "clockwise" or otherwise is relative to observer and therefore there's no point in asking that. Circular motion in original Bohr model was only an approximation and electrons move in unpredictable, chaotic way. Even on short timescales single atoms can be considered spherically symmetrical - they don't have left side or up side.

Mithoron
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  • The question does pose itself (and I am in no way qualified to understand that paper … I gave up quickly) whether electrons can be seen to circulate the nucleus or whether they just move randomly in its vicinity. – Jan Nov 02 '16 at 17:19
  • @Jan Bohr modelled orbits with circels Sommerfield improved with ellipses, but the movement is more or less chaotic https://en.wikipedia.org/wiki/Old_quantum_theory#Limitations_of_the_old_quantum_theory – Mithoron Nov 02 '16 at 17:30
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    @Mithoron You are confusing people for no reason. These papers do not say that an electron residing on an orbital moves in any literal sense. The second paper describes an excited electron which oscillates between certain states (each state being a probability cloud), and the first one deals with an ionized atom and separated electron. By skipping these technicalities, you fuel the false impression which many students already have, that electrons on (say) 1s orbital sort of fly around the nucleus, like planets around the Sun. This is quite wrong. Sorry, but you aren't making this clear. – Ivan Neretin Nov 03 '16 at 09:56
  • @IvanNeretin Well, for starters electrons do not reside on orbitals. Orbitals are only models, by no means a perfect ones. I felt the need to make this post because it's you who is wrong and I'll try to convince you. – Mithoron Nov 03 '16 at 20:48
  • Yeah, sure, if we look deeper, the orbitals are but abstractions and all that. Now what's about the electrons which are "moving"? In one case, an electron is oscillating between two probability clouds, which probably can count as "moving", but mentioning that without further explanation still does create a wrong impression. In the other case, an electron gets wrestled free from an atom and is moving in a somewhat classic fashion; that's OK. Now to the point: what about an electron in a ground-state atom, is it "moving"? – Ivan Neretin Nov 03 '16 at 20:58
  • @IvanNeretin See Dave's answer - http://chemistry.stackexchange.com/questions/13581/i-am-trying-to-picture-how-electrons-move-around-in-atomic-orbitals – Mithoron Nov 04 '16 at 17:40
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    The problem with the interpretations of quantum mechanics, and also the reason why there are so many of them, is that they are all equivalent when it comes to the observables. Bohmian trajectories, even if they exist, aren't and can't be seen. Your answer implies that the true trajectories of electrons in undisturbed atoms were actually observed. This is quite an overstatement. – Ivan Neretin Nov 04 '16 at 18:26