Molecular shape expanded valence shells

S2.3 The Lewis structures and molecular shapes for XcFi and ICb are shown below. The XeFi Lewis structure has an octet for the 4 F atoms and an expanded valence shell of 10 electrons for the Xe atom, with the 8 + (2 x 7) = 22 valence electrons provided by the three atoms. The five electron pairs around the central Xe atom will anange themselves at the comers of a trigonal bipyramid (as in PF5). The three lone pairs will be in the equatorial plane, to minimize lone pair-lone pair repulsions. The resulting shape of the molecule, shown at the right, is linear (i.e., the F-Xe-F bond angle is 180°). 

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