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Author Topic: Do atoms and electrons spin? If so, in which direction?  (Read 14666 times)

Offline jmcosta

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Hello,
well, in my mind questions, along my thoughts, I am wondering if Atoms/electrons ... spin/rotate they have to rotate in the same direction as the planets around the sun, anticlockwise, because if not it will against nature, what do You think?
Greetings
Joao
« Last Edit: 21/10/2013 23:35:04 by chris »


 

Offline JP

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Re: Atoms/electrons ... rotation
« Reply #1 on: 18/10/2013 16:07:31 »
This is a complex question: for fundamental particles like electrons, photons, etc. there is a property called "spin" which makes the particles act in some ways that are similar to classical spheres that are spinning about some axis, for example generating magnetic fields if they are charged.  In other ways, they don't act like classical spinning objects (for one thing, all attempts to measure their size have found that they are smaller than our best measuring devices, and smaller than they would need to be if they were real, spinning objects with the same physical properties such as magnetic fields).

For electrons orbiting atoms or other fundamental particles in orbits, there is something called orbital angular momentum, which means they act as if they are moving in some orbit, just like planets.  Again, this can be measured in terms of their effects when they strike something or the magnetic/electric fields they give off.  But we know that they don't quite behave like planets--for one thing, if an electron were orbiting the nucleus just like a planet, it would give off energy in the form of electromagnetic waves, and this would quickly cause it to spiral into the nucleus.  Electrons orbiting an atom actually act a lot like smeared out waves in many ways. 

With all those caveats, they still don't have the same spin/angular momentum as planets.  The reason is that the planets and sun formed from a spinning disk of matter, so they all rotate and revolve around the sun in a manner determined by this initial disk.  Fundamental particles and atoms are not formed by the same type of process, so they don't all rotate in the same direction.  In fact, there are rules that the electrons you put into an atom have to actually spin in alternating directions and have different angular momenta due to the odd rules of quantum mechanics.   
 

Offline Phractality

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Re: Atoms/electrons ... rotation
« Reply #2 on: 18/10/2013 20:37:11 »
Planets are held in orbit by gravity; electrons are held in orbitals by electromagnet forces. The electromagnetic between an electron and a proton is about 40 orders of magnitude stronger than gravity.
That's 10000000000000000000000000000000000000000 to 1.  As far as an atom is concerned, gravity doesn't exist, so the orbital plane of the planets has no effect on the internal structure of atoms.
 

Offline evan_au

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Re: Atoms/electrons ... rotation
« Reply #3 on: 18/10/2013 22:21:49 »
As someone living in the Southern Hemisphere, I challenge the notion that the planets orbit the Sun anti-clockwise. That direction is purely based on where you are standing (Northern or Southern hemisphere).

Planetary systems formed from different positions in a gas cloud would presumably have totally different orbital planes. So there is no single "right" direction of rotation for planets (or electrons).

While it is true that atoms are often shown with electrons orbiting the nucleus in concentric circles, in fact the electron orbits form 3-dimensional shapes. Only the "s" orbitals (eg the ground state for Hydrogen & Helium) is spherical; the others take on more complex shapes, see: https://en.wikipedia.org/wiki/Electron_configuration

Once the atoms form molecules, more orbital shapes appear, like hexagons or even more bizarre shapes.
« Last Edit: 18/10/2013 22:26:43 by evan_au »
 

Offline CliffordK

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Re: Atoms/electrons ... rotation
« Reply #4 on: 19/10/2013 00:21:25 »
Keep in mind that a bohr diagram is a poor representation of the actual form of atoms.  The electrons do not lie in a plane as planets do.  Perhaps with the partial exception of Hydrogen.

I believe typically the electron spin is "random".

There may be a few exceptions.

A strong magnetic field such as in an MRI or NMR can be used to temporarily orient the spin of all the hydrogen atoms in the same direction, but they rapidly revert to a random pattern once the magnetic field is released.

Permanent magnets (generally ceramic based), may also have a resonance pattern between the atoms, and thus, at least some of the electron orbitals would have the same orientation (which can be allowed to orient with the planet's magnetic field).
 

Offline evan_au

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Re: Atoms/electrons ... rotation
« Reply #5 on: 19/10/2013 08:02:00 »
Because electrons can travel throughout a piece of metal, electrons are not limited to orbit a single atom. The surface over which an electron can move is called the Fermi Surface. Some good visualisations here: http://www.phys.ufl.edu/fermisurface/
 

Offline syhprum

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Re: Atoms/electrons ... rotation
« Reply #6 on: 19/10/2013 13:53:23 »
Phractality

I think the actual ratio is more like 10^36 but I love your comma less representation of it
« Last Edit: 19/10/2013 13:55:08 by syhprum »
 

Offline Ophiolite

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Re: Atoms/electrons ... rotation
« Reply #7 on: 19/10/2013 14:39:56 »
Keep in mind that a bohr diagram is a poor representation of the actual form of atoms.  The electrons do not lie in a plane as planets do.  Perhaps with the partial exception of Hydrogen.
In what way is hydrogen an exception? I thought the probability function for the location of the electron was a spherical cloud around the proton. Am I mistaken? (I am likely using probability function very loosely here, but I hope my meaning is clear.)
 

Offline Phractality

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Re: Atoms/electrons ... rotation
« Reply #8 on: 19/10/2013 17:04:57 »
Phractality

I think the actual ratio is more like 10^36 but I love your comma less representation of it
The number of zeroes depends on whether you're talking about electron-electron repulsion, electron-proton attraction, or proton-proton repulsion. The electrostatic force field has the same magnitude for a proton or an electron, but the gravity differs by several orders of magnitude due to the different masses. The proton's mass is about 2000 times greater than that of the electron.
 

Offline Pmb

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Re: Atoms/electrons ... rotation
« Reply #9 on: 20/10/2013 05:58:15 »
Hello,
well, in my mind questions, along my thoughts, I am wondering if Atoms/electrons ... spin/rotate they have to rotate in the same direction as the planets around the sun, anticlockwise, because if not it will against nature, what do You think?
Greetings
Joao

Simply put - There is no reason to make such an assumption. And it turns out to be wrong anyway. And I'm not even sure what it means to 'Go against nature'. Do you mean "Break a law of physics"?  There is no law of physics that says that all objects must orbit in the same direction. In fact it seems quite concievable that an object could change their sense of orbit by interacting with other objects gravitationally. All that has to be done is to make sure the total angular momentum and energy is conserved in the process.
 

Offline Pmb

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Re: Atoms/electrons ... rotation
« Reply #10 on: 20/10/2013 06:01:15 »
Quote from: JP
The reason is that the planets and sun formed from a spinning disk of matter, so they all rotate and revolve around the sun in a manner determined by this initial disk.     
That doesn't apply to moons though. Our moon formed when a body smashed into the earth. Depending on how that collision occured the orbits could have been in different directions. Then there's the direction of orbit of the rings of planets. There's even one planet whose ringes are nearly perpendicular to the plane the planets are orbiting in. Do you know of any moons that orbit in the opposite sense than the body they're orbiting is rotating?
« Last Edit: 20/10/2013 06:05:43 by Pete »
 

Offline CliffordK

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Re: Atoms/electrons ... rotation
« Reply #11 on: 20/10/2013 09:29:54 »
Do you know of any moons that orbit in the opposite sense than the body they're orbiting is rotating?
Triton has a retrograde orbit to Neptune, and is thought to have been "captured".

I believe Venus and Pluto has retrograde rotation.
 

Offline evan_au

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Re: Atoms/electrons ... rotation
« Reply #12 on: 20/10/2013 19:37:34 »
Quote from: Ophiolite (source added)
I thought the probability function for the location of the electron was a spherical cloud around the proton.
This is true if it were possible to obtain an isolated hydrogen atom at absolute zero  - the electron will be in the spherical 1s orbital.

However, if the temperature is raised to achievable temperatures, the electron will jump between different orbitals as it absorbs and emits photons; many of these higher orbitals are not spherical.

If the hydrogen atom is not isolated in a vacuum, it will couple up with another hydrogen atom, forming H2; the electron cloud is no longer spherical, even at absolute zero.

The Bohr model of electron orbits is often represented diagrammatically in books as a flat plane with circular electron orbits - which looks very much like a diagram of our Solar System. This textbook simplification from 3D to 2D may have prompted the OP.
« Last Edit: 21/10/2013 10:59:31 by evan_au »
 

Offline Pmb

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Re: Atoms/electrons ... rotation
« Reply #13 on: 21/10/2013 07:37:12 »
Quote from: evan_au
Quote
I thought the probability function for the location of the electron was a spherical cloud around the proton.
This is true if it were possible to obtain an isolated hydrogen atom at absolute zero  - the electron will be in the spherical 1s orbital.
I don't understand something. Who are you quoting? I can't find any post in this thread where anybody said what you quoted. You also said "If" it were possible to obtain ... Why the "if" qualifier? There's no reason to use this since its quite possible for a hydrogen atom to be in that state. I fact I recall that most hydrogen atoms in a gas at room temperature would be in that state.
 

Offline CliffordK

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Re: Atoms/electrons ... rotation
« Reply #14 on: 21/10/2013 10:56:05 »
I thought the probability function for the location of the electron was a spherical cloud around the proton.
This is true if it were possible to obtain an isolated hydrogen atom at absolute zero  - the electron will be in the spherical 1s orbital.
Doesn't Helium also have a pair of 1s orbitals which are also described as spherical (and since it doesn't easily bond with other atoms, it would maintain a spherical shape. 

Other orbitals such as the p orbitals are generally described as non-spherical.
 

Offline evan_au

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Re: Atoms/electrons ... rotation
« Reply #15 on: 21/10/2013 11:16:10 »
Thanks, Clifford - I had to look up your instructions on attributing quotes!

Helium is a good example of spherical orbitals; however, Ophiolite specifically mentioned hydrogen, whose spherical electron cloud is often distorted by its strong tendency to bond with other atoms (including other hydrogen atoms).

I see that the transitions to and from hydrogen's ground state involve photons in the high-energy ultraviolet range, so although absolute zero might be unobtainable, I see that getting nearly all of the electrons in a hydrogen gas cloud into the 1s orbital looks relatively easy.
 
 

Offline Pmb

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #16 on: 22/10/2013 01:32:43 »
evan_au  - I don't know if you missed my question and that's why you didn't respond but I asked who you were quoting.
 

Offline flr

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #17 on: 22/10/2013 11:42:08 »
Keep in mind that a bohr diagram is a poor representation of the actual form of atoms.  The electrons do not lie in a plane as planets do.  Perhaps with the partial exception of Hydrogen.
In what way is hydrogen an exception? I thought the probability function for the location of the electron was a spherical cloud around the proton. Am I mistaken? (I am likely using probability function very loosely here, but I hope my meaning is clear.)

H is no exception, of course. Its 1s orbit is of spherical symmetry.   
 

Offline Phractality

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #18 on: 22/10/2013 20:17:40 »
There is a law of conservation of angular momentum. If the total angular momentum of the universe is zero, as appears to be the case, then things can't all spin in the same direction. That is what would be against nature.
 

Offline Pmb

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #19 on: 22/10/2013 21:28:52 »
However in curved spacetime you can't add angular momenta.
 

Offline jmcosta

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #20 on: 24/10/2013 07:26:14 »
Hi,
my daughter get seek, so I need to stay at home with her, no net in the village :)

Thanks for you answers, in some point I agree and understand them all, some of them are to physically constructed for the physics studies in my mind.

I'm happy anyway, this will give another perspective of life.

Why can't we travel in time?  If we came from the Big Bang all existing energy is in expansion, not in contraction, am I right? Energy is going into the infinite, there is no way back, only in huge modifications in the Universe will lead it to contraction, to the point 0. We know that atoms change their energy, electrons/photons, change their orbitals according to their levels of energy, if they loose energy they go to lower orbitals, yes? When they go back to the lower orbitals, after excitement then loosing energy, it does not mean that the energy is going back, it was just modified, action reaction.

Hardcore thoughts, maybe stupids :) but:
the big bang generate a stream of energy, in which we are in, we all loose and win energy, but we cannot go back in time to change our actions, as an atom, it gets excited then it looses energy, there is no way back, in a supposed sense of 'time', it act and react, it can not change its reaction, like us we act/react and we cannot go back in 'time' to change our actions.
If this stream that I mentioned exists, souls, if they exist they cannot go back in time, reincarnate, once energy is going into the infinite!!?

Obviously, energy is in evolution as we are as well, we were monkeys killing mammoths and now we seat in front of the computer ... evolution, maybe :)

[truncated - Mod]
« Last Edit: 24/10/2013 16:23:37 by peppercorn »
 

Offline spartaman64

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #21 on: 15/11/2013 03:21:40 »
not sure if atoms have a definite spin but yes electrons have quantum spin of 1/2 as does protons neutrons and neutrinos and quarks i think since its positive it goes up the angular motion on its axis because quantum spin is a vector. i think that quantum "spin" is just an analogy so not sure if it actually spins
 

Offline yor_on

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #22 on: 27/11/2013 02:24:55 »
I'm thinking of it slightly differently JM. My opinion is that 'time' exist. Also that it is due to 'c' and ones locally equivalent arrow we find things 'progressing', as in giving us ordered outcomes. One way to see it might be to consider the universe a projection of sorts. With the universe we observe real to us, living inside it. We, and everything we can measure, being 'natural outcomes' of those local constants and principles creating a 'commonly shared' universe, giving us distances and dimensions. But to make that work, one have to assume that what we observe is the veil, not what's behind it.
 

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Re: Do atoms and electrons spin? If so, in which direction?
« Reply #22 on: 27/11/2013 02:24:55 »

 

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