octet expansion

[Roni Touboul]

what does it mean when lavelle said "octet expansion involves d-oribtals"?

[Hai-Lin Yeh 1J]

The reason to the octet expansion involving d-orbitals is because if n=2, the second row of the periodic table, the electron configuration would only be s2p6, which involves no d-orbitals, therefore, aren't allowed for octet expansion. On the other hand, if n=3, you can recall that l would equal to 0, 1, and 2 and that corresponds to s, p, and d orbitals respectively. Thus, if n=3, d-orbital exists. Therefore, elements in the third row will allow for octet expansion because the d-sublevel can accommodate more bonding with other atoms whereas the n=2 does not have a d-sublevel, which means it cannot be expanded.

[Millicent Navarro 1I]

A quick way to think of the "octet expansion involving d-orbitals": Elements that would be considered to have an expanded octet are those in period 3 and beyond because these specific elements can/are able to hold electrons in the d-orbital shell.

Hope this helps.