Electron cloud confusion

Discussion in 'Chemistry' started by azerym, Sep 19, 2007.

  1. Reiku Banned Banned

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    Also, i've just edited post 17 after a small error. Please read this again before you do any work.
     
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  3. oski369 Registered Member

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    I wont be visiting this site again until my project is already over, but just outa curiousity, whats spin mean, we just started our chemistry unit, and if up and down are the only options how can 8 electrons be on the same level.
     
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  5. Reiku Banned Banned

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    Spin is a classical concept... and it turns out that nobody actually knows what it is, but we describe them with sideways, up or down, ect.
    But you noted that 8 would be wrong. A paradox. That would be right, and well spotted too. So, we have to give the electrons energies as well. So two particles can have two up spins, just so long as they have different energies. I didn't want to explain this to you, because it just complicates things.
    But well done you for spotting that.
     
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  7. Reiku Banned Banned

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    The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925. This principle is significant, because it explains why matter occupies space exclusively for itself and does not allow other material objects to pass through it, while at the same time allowing light and radiation to pass. It states that no two identical fermions may occupy the same quantum state simultaneously. A more rigorous statement of this principle is that, for two identical fermions, the total wave function is anti-symmetric. For electrons in a single atom, it states that no two electrons can have the same four quantum numbers, that is, if n, l, and ml are the same, ms must be different such that the electrons have opposite spins.

    Wikipedia
     
  8. Nasor Valued Senior Member

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    I don't think there are any really good analogies for electron clouds. Their quantum nature doesn't relate well to anything in the macroscopic world. I mean, a particle that's described as a wave? A particle whose location can only be described as a probability function? A probability function that has areas separated by nodes??? That last part alone is enough to give you a headache if you spend too much time trying to relate it to anything in the macroscopic world.
     
  9. Reiku Banned Banned

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    Tell me about it... i had a headache last night writing this stuff for this chap.... and i'm not joking...
    I don't think i had myself actually contemplated how strange the electron world is really... and i was the one writing about it!
    I just hope the boy/girl does well. I hope they report their score.
     
  10. Nasor Valued Senior Member

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    Meh. It's pretty same to assume that whoever will be grading him knows close to zero about orbitals anyway.
     
  11. oski369 Registered Member

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    Reiku thank you for all your help. Today I recieved my grade, I got a 96, the only points taken off were because i didnt connect my poster with my speech, and I was 4 seconds under 2 minutes, the target time.
     
  12. Reiku Banned Banned

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    I'm pleased for you. You're welcome.
     
  13. superluminal . Registered Senior Member

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    This is so... almost right.

    An electron (or other quantum entity) cannot have both its position and momentum determined simultaneously. Electrons in an atomic "orbit" occupy regions defined by their wave functions (probability distributions). Measuring the position or momentum of an electron instantly disturbs the other properrty and vice-versa, collapsing its wave function to a precise value.

    Saying the electron is "in more than one place at one time" is not true. An electron is a particle with a probability of being in a certain location with a certain momentum at a given time.
     
  14. Reiku Banned Banned

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    Note superluminal, that to say the electron is in more than one place at one time, is ethereal in character. Let us not get mixed up with the real and virtual properties.
     
  15. superluminal . Registered Senior Member

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    10,717
    Ok.
     
  16. Reiku Banned Banned

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    Classical theories run the show without the quantum wave function. Even relativity is classical.
     
  17. kaneda Actual Cynic Registered Senior Member

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    Measuring where an electron is is like measuring where a football is by kicking it. Of course it moves to another position. However we should be able to plot exactly where it is, so to speak. Since an electron has an orbit which would only become obvious after some study (and not just a standard orbit like a moon), it would be very difficult to work out, being influenced by a number of forces. Ultimately it is like trying to measure where a football is as several players from both teams struggle for it outside the mouth of a goal.
     
  18. Reiku Banned Banned

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    That's a good description.
     
  19. kaneda Actual Cynic Registered Senior Member

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    If we know how much repulsive force an electron has, how much attractive force a proton has, how many electrons there are and what speeds they are moving at in what shells, I would think it possible to measure their probable positions at all times based on their interactions with each other, in a single atom. With other atoms, depending on the state whether solid, liquid or gas and depending on the temperature, we could then take into account the effect of the electron shells and nucleii of other surrounding atoms on these electrons. Once we get into molecules it of course becomes more difficult.
     
  20. Sciencelovah Registered Senior Member

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    Just wanna add an illustration to those has been explained elsewhere in this thread.
    Following image is cropped from here.


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    Other illustration:

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  21. Reiku Banned Banned

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    Good work.
     
  22. Sciencelovah Registered Senior Member

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    Thanks. In fact, I learn a lot from you and from other people as well.
     

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