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Electronegativity difference NaH

  1. Nov 2, 2009 #1
    Although the electronegativity difference between sodium and hydrogen in NaH is less than 1.7 , it is ionic bond WHY??
     
  2. jcsd
  3. Nov 2, 2009 #2

    chemisttree

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    Who told you it was ionic?
     
  4. Nov 2, 2009 #3
    Any alkaline metal hydride is ionic

    Ionic hydrides
    Ionic or saline hydride, is a hydrogen atom bound to an extremely electropositive metal, generally an alkali metals or alkaline earth metals.
    source:http://en.wikipedia.org/wiki/Hydride#Ionic_hydrides
     
  5. Nov 2, 2009 #4

    chemisttree

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    Do you think it is purely ionic or might it have a bit of covalent character to it?
     
  6. Nov 2, 2009 #5
    I think it is purely ionic because for metals with weak metallic bond like alkaline metals it's a must to lose its valence electron completely for them they are are rarely found in covalent compounds.
     
    Last edited: Nov 3, 2009
  7. Nov 3, 2009 #6

    alxm

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    Bah, everything's got a bit of a covalent character to it and vice-versa :) Do the actual QM calculations and you won't find nice integers popping up very often..
     
  8. Nov 3, 2009 #7
    Thanx 4 enrichin me by this info in fact my study is somehow limited cuz am still in high school I didn't study QM calculations
     
  9. Nov 4, 2009 #8
    Hi,

    This is the same as, I have heard about as, this is what I have studied in my time.

    Thanks!
     
  10. Nov 4, 2009 #9

    chemisttree

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    With an electronegativity difference of only 1.7 it is likely a very polarized covalent bond or an very covalent ionic bond. Semantics.
     
  11. Nov 6, 2009 #10
    The only way I can tell to distinguish the two cases is on a macroscopic level. Lets face it, on a quantum level there's basically no straightforward way of telling ionic from covalent. (all the atoms are in a lattice and there's electrons everywhere)
    So, if you hit a large crystal of NaH with a hammer, would it shatter? if you melt NaH (in an inert atmosphere), will it conduct electricity?
    My gut says yes to both, and therefore I would say NaH is ionic.
     
  12. Nov 8, 2009 #11
    Yea its a Ionic Compound ( due to its properties) with more Covalent Character : )
    We know nothing is Purely(100%) ionic or covalent : )
     
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