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Lewis dot structure, octet rule for a central atom

  1. Mar 21, 2014 #1
    As you can see, octet rule isn't satisfied for the central atom Xe, it has 2 more electrons attached to it.
    So does it mean, that you should first try to make sure octet rule works for any "side" atoms, and then you just put any remaining electrons to a central atom? (or central atoms?) And if Central atom has more than 8 electrons attached to it, you just leave it like that, right? Because there's no way to fix it with multiple bonds, right?

    I understand why double bond is impossible between two Carbons here, but what if there were only two Hydrogens in the compound (acetate ion), would it mean that there could be a double bond between Carbons as well?

    #3. Lastly, can there be more than 1 central atom? Like in the previous example, both C are central atoms, right?
    Last edited: Mar 21, 2014
  2. jcsd
  3. Mar 21, 2014 #2


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    For point 1, you pretty much got the picture. Indeed what you call 'exterior' atoms do indeed have the smallest number of covalent bonds, so their octet structure is easier to achieve. Because you can't get a Florine atom to have a double bond (that would ruin its octet, Florine is the only one for which its octet is holy), it is always an 'exterior' atom.

    Point 3. It's correct. CH_3-CH_3 is another example.
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