Shapes with Six Electron Groups Octahedral Arrangement

Molecular Shapes with Six Electron Groups (Octahedral Arrangement) 

With six bonding groups, the molecular shape is octahedral (AXg), as in sulfur hexafluoride (SFg)  

Because all six electron groups have the same ideal bond angle, it makes no difference which position one lone pair occupies. Five bonded atoms and one lone pair define the square pyramidal shape (AX5E), as in iodine pentafluoride (IF5)  

When a molecule has four bonded atoms and two lone pairs, however, the lone pairs always lie at opposite vertices to avoid the stronger 90° lone pair-lone pair repulsions. This positioning gives the square planar shape (AX4E2), as in xenon tetrafluoride (XeF4)  

Using VSEPR Theary ta Determine Malecular Shape 

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