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Topic: Electron  (Read 2705 times)

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Offline qasim4593

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Electron
« on: October 27, 2016, 10:21:07 AM »
According to Rutherford and Neil Bohr model of an atom, electrons revolve around the nucleus to keep themselves away from the nucleus (as nucleus attracts electrons towards itself).How electrons keep themselves away from the nucleus if they don’t revolve around the nucleus? If electrons don’t revolve around the nucleus, then they should fall into the nucleus and structure of atom should collapse. But it does not happen, why???

Sincerely,
Qasim
« Last Edit: October 27, 2016, 10:53:36 AM by qasim4593 »

Offline Arkcon

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Re: Electron
« Reply #1 on: October 27, 2016, 10:43:18 AM »
Correct.  The Bohr and Rutherford models explain some phenomena, but not all.  So they have been replaced with newer models.  Read ahead on your textbook, and you'll see how those models work.
« Last Edit: November 11, 2016, 08:18:59 AM by Arkcon »
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Enthalpy

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Re: Electron
« Reply #2 on: October 27, 2016, 11:57:58 AM »
Maybe the query was: "if electrons don't rotate in models more recent than Bohr, why don't they fall"?

The answer to this would be: yes, they fall. All s orbitals have their maximum of probability density per volume unit at the nucleus.

But electrons don't concentrate at the nucleus because they are waves and as such, have a volume. And in a more detailed manner: concentrating the electron in a smaller volume implies a higher kinetic energy, which counters the advantage of proximity to the positive nucleus. There is an optimum which is the atom's radius.

Offline Enthalpy

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Re: Electron
« Reply #3 on: October 27, 2016, 12:20:17 PM »
As a sidenote, "electrons don't rotate" is tricky.

As s orbitals, they don't.

As other orbitals, it's less simple. The probability density (hence the absolute value of the wavefunction) doesn't move, that's why such solutions are called "stationary", and the electron doesn't radiate. But the phase of the wavefunction does change over time and, at some angular moments, the phase rotates around the nucleus. This rotation defines an angular moment despite the solution is stationary.

And then, you have the wavefunctions for electrons that are trapped in atoms but are not orbitals. We know all wavefunctions for trapped electrons are linear combinations of orbitals, but these are not stationary: their absolute value moves over time. If you take [1s+2px]/sqrt(2) for instance, the electron has a bulge in its probability density, and if the 2p has an angular momentum of 0 the electron wobbles over the x axis, while an angular momentum of 1 lets the bulge rotate around the nucleus near to the yz plane.

This latter case resembles a classical rotation, just more fuzzy than a planet around a sun, and it does radiate or absorb an electromagnetic wave and is unstable.

Offline AdiDex

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Re: Electron
« Reply #4 on: October 28, 2016, 02:24:12 PM »

you have the wavefunctions for electrons that are trapped in atoms but are not orbitals. We know all wavefunctions for trapped electrons are linear combinations of orbitals, but these are not stationary: their absolute value moves over time. If you take [1s+2px]/sqrt(2) for instance, the electron has a bulge in its probability density, and if the 2p has an angular momentum of 0 the electron wobbles over the x axis, while an angular momentum of 1 lets the bulge rotate around the nucleus near to the yz plane.


I think this is the "High School Chemistry Forum"  ;D  Please Don't Scare him .

Offline AdiDex

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Re: Electron
« Reply #5 on: October 28, 2016, 02:38:45 PM »
For Now, you have to know that if you think electron just like a particle you will get confuse . May be after some time you will face a term called "Wave-Particle Duality" . So electron is not just a particle but both wave and particle at the same time . It is not revolving around the nucleus , but it is bound to the nucleus . You can describe it as Stationary wave .

So daily intuitions are not exactly valid on Quantum Realm (At the atomic level).

P.S.
In reality Electron is neither a particle nor a wave ,' It's the limitation of our language that we can't explain it's behavior in the simple words . Saying that it has wave-particle duality is valid in limiting case' - W. Heisenberg . 

Offline AdiDex

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Re: Electron
« Reply #6 on: October 28, 2016, 02:42:02 PM »
You can check out the video of Minute Physics
https://www.youtube.com/watch?v=Q_h4IoPJXZw.

Offline Enthalpy

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Re: Electron
« Reply #7 on: October 30, 2016, 07:29:52 PM »
I think this is the "High School Chemistry Forum"  ;D  Please don't scare him.
True. Then, the electrons have already fallen on the nucleus, but keep a volume because they're waves, and that's the atom's volume too.

A nice site for orbitals:
http://winter.group.shef.ac.uk/orbitron/

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