Why can we not say Water exist in 4 phases

Discussion in 'Chemistry' started by timojin, Dec 16, 2015.

  1. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    There's very little that river says that makes sense.
     
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  3. river Valued Senior Member

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    How did I know dywdyr would soon come in here and say this.

    But the little that makes sense; makes sense.
     
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  5. river Valued Senior Member

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    Look for a lab. that can isolate one ; single atom of any type ; with the ability to bring it down to minus 280 kelvin.
     
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  7. exchemist Valued Senior Member

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    No indeed. Nor did it two and a half years ago, when we went through it the first time with river.

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    And nor does the idea of a temperature, for an isolated molecule, atom or ion. This however is a more complicated issue, so I don't blame river for not understanding it. For any interested readers, there is what strikes me as a good discussion of it here:

    http://chemistry.stackexchange.com/questions/24218/temperature-of-an-atom

    If you do not have an ensemble of atoms molecules or ions, with a Boltzmann distribution of kinetic energy, you do not have a well-defined temperature.
     
  8. river Valued Senior Member

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    We don't have a well defined temperature ; irrelevent ; just bring the atom of H and O to the point of the manifestation of a liquid .
     
  9. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    No it doesn't.

    Don't be stupid.
    A minus kelvin value makes no sense.

    No: a single atom can't be liquid.
     
  10. river Valued Senior Member

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    True
     
  11. river Valued Senior Member

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    Prove it .
     
  12. exchemist Valued Senior Member

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    In fact, if I recall correctly, the issue of so-called "negative temperature" has come up in some journalists' reports in the last few years and we did discuss it on the other forum, I think.

    What they mean however is a population inversion, i.e. involving a non-Boltzmann energy distribution. This can sometimes be modelled with a +ve exponent in the exp(-ε/kT) terms of the distribution functions, which implies a -ve value for T. But it is a quite artificial, non-equilibrium distribution, and so the concept of temperature cannot really be applied to it. It seems to me that negative temperature is journalistic hype, possibly abetted by researchers looking for media coverage. Certainly in the more fundamental sense of temperature as that which indicates the direction of spontaneous heat flow, these "negative" temperatures are not negative at all, because the unstable population inversion will eventually collapse, with release of energy.
     
  13. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    This is deeply ironic on at least two counts:
    1) You're the one that effectively made the claim - i.e. a single atom being liquid but apparently it's necessary for you to "prove" that this is possoble. (IF you knew anything then you'd know that it's the arrangement/ connections of atoms that make a substance water rather than solid or liquid - a single atom is just an atom).
    2) You have a history of making claims that you refuse to support let alone "prove", so why should I have to bother "proving" anything to you?
     
  14. river Valued Senior Member

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    Explain again
     
  15. DaveC426913 Valued Senior Member

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    river, what makes you think this? You confess you don't know a lot about the physics of molecular states.
     
  16. exchemist Valued Senior Member

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    To you? I think I'd have more luck teaching calculus to my cat.

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    Once you've understod why an isolated molecule, atom or ion cannot be said to be in a liquid or solid state, maybe we can discuss this. But not before.
     

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