From: poutnik4nntp@gmail.com   
      
   Dne 05/12/2016 v 07:39 Poutnik napsal(a):   
   > Dne 05/12/2016 v 05:29 Hussein Shareef napsal(a):   
   >> Hello   
   >> I was reading about the octet rule exceptions and it said that SF6 is one   
   of those exceptions because it has more than 4 bonds therefore more than an   
   octet, but it also said that the electrons will ill the 3d orbital, that is   
   the part that didn't make    
   sense to me, why would the electrons fill the 3d orbital before the 4s   
   orbital, isn't the 4s orbital lower in energy then the 3d?   
   >>   
   > Relative energy of orbitals is not fixed across the elements,   
   > but depends on kernel charge   
   > and number and quantum states of present electrons.   
   >   
   > E.g. for hydrogen atom, the 4s has higher energy than 3d,   
   > as for 1 electron atom the obital energy is given   
   > by main quantum number. (if we neglect some fine QED effects ).   
   >   
   > So relation of 4s and 3d shifts with increasing number of electrons.   
   >   
   > But for molecules, is is matter of molecular orbitals   
   > as linear combination of atomic ones.   
   >   
   > Those 6 d2sp3 orbitals of SF6 are combinations   
   > 3 of 3p, 1 of 4s, 2 of 3d.   
   >   
   Should be 6 sp3d2 = 1 3s 3 3p 2 3d   
   d2sp3 would be 2 3d 1 4s 3 dp   
      
   See also   
      
   http://www.meritnation.com/ask-answer/question/what-is-the-diffe   
   ence-between-sp3d2-and-d2sp3/coordination-compounds/3796525   
      
      
      
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   Poutnik ( The Pilgrim, Der Wanderer )   
      
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   as they say about him more,   
   than he says about the subject.   
      
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