elements in 3p block

[Nare Arakelian Dis 3E]

Why are Phosphorus, Chlorine, and Sulfur exceptions to the octet rule when their electron configurations do not have a 3d orbital? Is it just because they are in the third energy level?

[Robin Cadd 1D]

They do have a 3d subshell, it's just not filled.

[Brittany Tran 3I]

period 3 elements can utilize their 3d orbital to form expanded octets, but the 3d orbital doesn't have to be occupied, like in the case of P, S, and Cl

[Katie Kyan 2K]

If we look at the quantum number for the period 3 elements like P, S, and Cl we see that for n=3, l=0,1, or 2. Even though for the ground state electron configuration, the electrons of the period 3 elements do not fill the d orbital, they have the ability to as we can see from the angular quantum number taking on the possible value of l=2. Therefore, elements in row 3 can have expanded octets and make use of their empty d orbital to hold electrons.

[Michelle Xie 2B]

They are able to use their 3d orbital. They are just normally not filled.

[Nuoya Jiang]

Their n=3, which indicates that they are able to have 3d orbitals.

[anjali41]

Elements in the 3p block actually can have a 3d orbital, but the orbital does not have to be completely filled in the case of some elements.

[Nare Arakelian Dis 3E]

Thank you guys for answering! This cleared up a lot for me!

[Adelpha Chan 1B]

Why are Phosphorus, Chlorine, and Sulfur exceptions to the octet rule when their electron configurations do not have a 3d orbital? Is it just because they are in the third energy level?

Though themselves do not normally occupy the 3d orbital, n=3 meaning that the d orbital (l=2) is available, therefore allowing for an expanded octet