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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: athrun on March 22, 2006, 08:40:42 PM

Title: why are fully filled and half filled sub shells more stable?
Post by: athrun on March 22, 2006, 08:40:42 PM

why are fully filled and half filled sub shells more stable?

what are the reasons for the above?

thx!

Title: Re:why are fully filled and half filled sub shells more stable?
Post by: Moonshyne on March 23, 2006, 01:02:23 AM

I think it's because it takes less energy to store an electron in a half-filled or completely-filled d shell rather than a filled s shell. Like in Cr with the electron configuration [Ar]4s¹3d⁵, the last valence electron goes to the 3d shell instead of the 4s shell because it takes less energy to store it in 3d.
-hope this helps

Title: Re:why are fully filled and half filled sub shells more stable?
Post by: xiankai on March 23, 2006, 03:14:47 AM

the 3d subshell has a higher energy associated with it compared to the 4s subshell, so i think its related Pauli's exclusion principle...

where each electron would prefer to have its' own orbital as compared to sharing one with another; in this case mutual repulsion between the 4s1 and 4s2 electron is not preffered to all 6 electrons occupying their own orbits with minimal interference from each other other electron.

thats what i was taught..

Title: Re:why are fully filled and half filled sub shells more stable?
Post by: athrun on March 23, 2006, 06:22:49 PM

hey moonshyne and xiankai, thx for the *delete me*

does make more sense now
 :)