Hund's rule

[salsero]

Does Hund's rule also apply when combining the angular momenta of electrons from shells with DIFFERENT quantum number n?

[Tom Mattson]

I'm not sure of what you mean. Hund's rule does not have to do with "combining angular momenta", but rather with filling subshells.

[salsero]

Suppose there are n electrons with angular momentum quantum numbers L1, L2, L3, ..., Ln. The total angular momentum L of the atom can be any number between the minimum and the maximum of all non-negative combinations +/- L1 +/- L2 +/- L3 ... +/- Ln (in steps of 1). Same about combinations of the spin (the spin quantum numbers of the single electrons are always 1/2) to the total spin S of the atom.

Hund's rule says that the lowest-energy state among all the possible states is the state which has the greatest S and the greatest L (for that S).

[QuantumNet]

Originally posted by salsero
Suppose there are n electrons with angular momentum quantum numbers L1, L2, L3, ..., Ln. The total angular momentum L of the atom can be any number between the minimum and the maximum of all non-negative combinations +/- L1 +/- L2 +/- L3 ... +/- Ln (in steps of 1). Same about combinations of the spin (the spin quantum numbers of the single electrons are always 1/2) to the total spin S of the atom.

Hund's rule says that the lowest-energy state among all the possible states is the state which has the greatest S and the greatest L (for that S).

If it's true in two cases, it's true in all (in this case)

Best wishes

[salsero]

What???