Hund's Rule

[Jessica Tejero 3L]

When writing an electron configuration how does the Hund's rule come in? Is it only when more than one orbital in a subshell is available? Or is it when their spin numbers are paired?

[JamieVu_2C]

Hund's rule basically states that for a subshell with multiple orbitals, then you fill each orbital with one electron first before you fill a single orbital with two electrons. So for example, when you're filling in the p-orbitals, you fill up the px-, py-, and pz-orbitals with one electron each before you fill up the px-orbital with two electrons. The spin numbers are paired when you're filling up the separate orbitals with one electron.

[Chem_Mod]

Hund's rule is filling out orbitals with single same spin electrons before you pair them up in the same orbital. Pauli exclusion principle relates to 2 electrons in the same orbitals must have opposite spins.

[Vivianvelazquez_1J]

I'm not sure if I completely understand the question but what I know about Hund's rule is that every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).