octet expansions

[Sandra Kim 2B]

In the recent lecture, Dr. Lavelle said that octet expansion involves d-orbitals but I feel like I have seen instances where elements like Si, P, and S have had expanded octets in their Lewis structures. Where do the d-orbitals come into play with these elements in the 3p orbital or is my brain messing with me?

[Abby Lam 3F]

Elements in 3p can have expanded octets because there is an empty 3d orbital nearby. I believe expanded octets go into the next orbitals (s,p,d,f) in the same subshell (n=3,4,5..). Elements in 2p cannot have an expanded octet because there is no 2d orbital.

[Sondia Luong 1C]

The d-orbitals are involved in expanding the octet because they allow for elements in the p-orbitals to expand. Usually, when drawing Lewis structures, the elements with expanded octets will be after the 2p orbital. I believe we won't be encountering d-orbital elements with expanded octets.