Why does the Lewis structure of XeF4 not follow the octet rule?

1 Answer
Jul 15, 2017

Answer:

The octet rule states that atoms want to fill their outer valence shell with 8 electrons, this molecule defies this rule because in seeking a formal charge of 0, #Xe# accumulates 12 total electrons.

Explanation:

The Lewis Structure for this molecule is:
Geometry of Molecules

The octet rule states that atoms seek to surrounded by 8 electrons each to fill their valence shells. This rule is not law, and has various exceptions regarding transition metals, but for noble gases and group period 1-3 elements, it's fairly reliable.

So, applying this rule to the above structure, we see that #Xe# has four bonding and two nonbonding pairs of electrons; which it is and isn't sharing with the fluorine atoms.

Its formal charge is 0, but it has 12 electrons surrounded about it. Hence, it doesn't follow the octet rule.