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Liquid Sodium?

  1. Oct 31, 2005 #1


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    Liquid sodium can exist at room temperature at EXTREMELY high pressures. Why?
  2. jcsd
  3. Oct 31, 2005 #2

    Claude Bile

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    Any liquid can exist at any temperature provided the pressure is high enough (except of course at temperatures where the substance in question does not have a liquid state such a dry ice).

  4. Nov 1, 2005 #3
    That must be because there is a liquid phase with higher density.

    Normally, sodium crystallizes in the body-centered cubic (bcc) structure, which is not close packed. At high pressures there is probably a transition to cubic or hexagonally close packed. This structure may have a melting point below room temperature.
    Last edited: Nov 1, 2005
  5. Nov 1, 2005 #4


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    This is exactly right, but it appears that there's more to it than just that. Most metals that lack a close-packed structure exhibit some degree of negative melting. In sodium, however, this is unusually strong.

    There's a very recent paper on this that I've yet to read : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000094000018185502000001&idtype=cvips&gifs=yes [Broken]

    http://physics.about.com/od/thermodynamics/a/roomtempNaLiqui.htm [Broken]

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