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Homework Help: The bonding in aluminium oxide

  1. Oct 12, 2008 #1
    Does anyone know firstly what this type of formula is called: H-H, i know that it describes the bonding but can't remember what it is called :O

    Secondly, how would i show the bonding in aluminium oxide usingthis type of formula?
  2. jcsd
  3. Oct 12, 2008 #2


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    Staff: Mentor

    My bet is structural formula, although they are mostly used for organic compounds.
  4. Oct 13, 2008 #3


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    Science Advisor

    You can't really write salts as individual molecules since that's not how salts work. There is no such thing as an aluminum oxide molecule just as there is no sodium chloride molecule. The chemical formula is only to show a ratio between atoms; there is no implied shape.

    If you are trying to go ahead and do it anyway, draw the aluminum first. Metals cannot make covalent bonds, so that would restrict any Al-Al bonding. Oxygen to oxygen bonds are extremely unstable, so try avoid that as well. Al makes 3 bonds, oxygen makes 2. If I had to randomly guess the shape of this nonexistent molecule and I had to follow all of the rules I just said, I would think something like O=Al-O-Al=O. Each oxygen has 2 bonds, each aluminum has 3, there are no Al-Al and no O-O bonds. This looks right, but it's completely wrong. Don't draw salts like this.

    Here is the actual shape. Notice how what I wrote is way off.
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