Spin States and Hund's Rule

[Khoa Vu 3l]

Knowing that Hund's rule states that you must fill degenerate orbitals with one electron before you start pairing them up, my question is that does it matter which spin state fills up each orbital first? For example, we fill each p orbital with a spin down electron (-1/2) first instead of a spin up electron (+1/2) like Dr. Lavelle showed us in his examples. There seems to be no principles or rules that say otherwise, so I thought I would just ask here.

[SophiaNguyen_2L]

Hello! I might be wrong, but I don't think it really matters which way the electron spins first. I think Professor Lavelle and other educators tend to write that the electron spins clockwise first because the arrow signifying that tends to be written on the left first, if that makes sense. So to answer your question: no, it doesn't matter which direction the first electron filling up the orbital spins.

[Truman Chong Dis 3G]

I don’t think direction matters for Hunt’s rule as long as electrons in different orbitals are the same direction. For example, writing p^3 you would have 3 arrows in 3 different orbitals all pointing in the same direction to maximize spin.

[Joey_Okumura_1E]

It does not matter which spin is first because the spin number is assigned arbitrarily. The only thing that matters is that the unpaired electrons in different orbitals have parallel spins and paired electrons have opposite spins.

[Tanner Bartyczak 1K]

I was also wondering this. Thanks for the explanations.

[Marco Vivar 3G]

I don't believe it matters but make sure to have them all spinning the same way if they are unfilled for example all -1/2 or all 1/2

[Binyu You]

I agree with Joey! I believe that direction really does not matter that much, what is more important is to make sure they all spin in the same way.

[Adam Bustamante 1I]

I don't think the direction matters when writing the arrows, but if you start with a spin down arrow and are filling the other shells with Ione arrow each, then you'd want to continue with the spin down arrows.

[Kelly Tran 1J]

I don't think the direction of the spin state matters as long as Hund's rule is applied correctly. However, the spin up state is typically drawn first in each orbital and then the spin down state is drawn.