Noble gas exception

[Michelle Pham_3H]

Today in lecture, we discussed the Lewis structure for xenon tetrafluoride and how it can accommodate 12 electrons (4 single bonds, 2 lone pairs). Based on what we have learned, we know that S, P, and Cl can have more than an octet. Why can xenon have more than an octet, and are there any other similar exceptions? Thanks in advance!

[Amy Zheng 2l]

d orbitals can fit more electrons

[Leanne Wong 1H]

Unlike s and p orbitals, d orbitals can expand beyond the octet rule and xenon is so low on the periodic table, therefore, Xe is able to hold more than 8 electrons.

[Jasmin Tran 1J]

Also in the midterm review today, the UAs basically said that an atom of P, S, Cl or another nonmetal in Period 3 and subsequent periods can have more than 8 electrons in it's valence shell because they have more orbitals available to them (ex. the d subshell). Hope this clarifies a bit more!

[Yixin Angela Wang 2H]

To add on to what is being discussed, a UA in a midterm review today said that the maximum amount of electrons an expanded valence shell can have is 12.