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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: alexmahone on July 02, 2012, 11:06:42 PM

Title: Why is the electron affinity of boron less than that of lithium?
Post by: alexmahone on July 02, 2012, 11:06:42 PM

In general, electron affinity increases across a period. Then why is the electron affinity of boron (27 kJ/mol) less than that of lithium (60 kJ/mol)?

Title: Re: Why is the electron affinity of boron less than that of lithium?
Post by: Schrödinger on July 03, 2012, 01:33:21 AM

I guess its because Li goes from half filled 2s to fully filled 2s. But B on the other hand, on gaining an electron doesnt get that sort of help from its p-orbital, which continues to be partially filled.

Title: Re: Why is the electron affinity of boron less than that of lithium?
Post by: alexmahone on July 03, 2012, 02:23:50 AM

Quote from: Schrödinger on July 03, 2012, 01:33:21 AM

I guess its because Li goes from half filled 2s to fully filled 2s. But B on the other hand, on gaining an electron doesnt get that sort of help from its p-orbital, which continues to be partially filled.

Thanks a lot!