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Homework Help: Why is LiBr ionic?

  1. Oct 16, 2011 #1
    Li (Electronegativity) = 1.0
    Br (Electronegativity) = 2.8

    2.8 - 1.0 - 1.8

    Ionic = 2.0+
    Polar = .4 - 2.0+
    Non polar covalent = 0 - 0.4

    1.8 doesn't it fall into the polar range? I got that wrong on a h.w. question
     
  2. jcsd
  3. Oct 16, 2011 #2
    We round the electronegativity of lithium to 1.0, and bromide to 3.0, so the difference is actually 2.0.

    It is also ionic because it is a bond between a metal and non-metal.
     
  4. Oct 17, 2011 #3

    Borek

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    Staff: Mentor

    This is way too handwavy for my liking. Selectively rounding you can prove anything, including 0=1.

    So why is AlCl3 covalent?
     
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