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Exceptions to Electron Affinity

Posted: Sun Nov 04, 2018 1:44 pm
by Bianca Barcelo 4I
Hi, I was wondering what were the exceptions to electron affinity that we had to know?

Re: Exceptions to Electron Affinity

Posted: Sun Nov 04, 2018 2:16 pm
by 905109118
Bianca Barcelo 1G wrote:Hi, I was wondering what were the exceptions to electron affinity that we had to know?


This exception rule is actually orbital filling rule. For two electrons to be in same orbital they need to have different spins (Pauli exclusion principal). This electron pairing requires additional energy and thus it is easier to add electrons if there are free orbitals. When element has a half-filled p sublevel all 3 orbitals have one electron and pairing takes place (difference between energy levels of 2p and 3s is greater than electron pairing energy).