Chemistry / Unit 5 Chem 0850 short lesson, about 20 seconds
Hund's Rule
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The idea
Hund's rule states electrons fill degenerate orbitals singly, with parallel spins, before any orbital in that set gets a second electron.
In practice
Nitrogen's three 2p electrons each occupy a separate 2p orbital with parallel spin, rather than pairing up in fewer orbitals.
Where people slip
Pairing electrons early, before every orbital in the set holds one, violates the arrangement Hund's rule predicts.
Your place on the trail
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Builds on
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