Valence Config question

[Jo07]

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Can someone explain this to me?

Group VB valence electron configuration of d^3 s^2
Group VIB -- s^1 d^5

I understand how the Group A's fill, but not these...

Thanks!

 

[Lonely Sol]

Can someone explain this to me?

Group VB valence electron configuration of d^3 s^2
Group VIB -- s^1 d^5

I understand how the Group A's fill, but not these...

Thanks!

It is because of Hunds rule, which states, electrons will try to make the most 1/2 filled orbitals possible. So, it is easy for the electron to be excited to the d orbital, which makes it more stable.

*plz correct me if I am wrong!

 

[Ms.Dentista]

why should we correct you if you are right?😀

 

[sacjumpman]

Pretty much what lonelysol said.

Just memorize that Cr and Cu are the exceptions to the way in which their orbitals fill up.

Cr is 4s13d5

Cu is 4s13d10

Those are the only exceptions I'm aware of.

 

[Jo07]

Sorry guys, I'm still lost on that. I completely understand how any of the representative elements fill. But then how does VB just go straight to d3s2 and VI B first goes s1d5??

 

[151AND8TH]

I am only aware of those 4 exeptions.. Cr/Cu and Mo/Ag.... I didnt know the whole groups did not follow the pattern of e configuration. I am almost positive that those 4 are the only one, at least for what we should be concerned with.. I remember being told to JUST MEMORIZE this.. and figure it out when you get to some super dupper upper level chem class 🙂

 

[Jo07]

Okay, thanks!

 

[wahoo08]

i was just about to post the same question! thanks to everyone that replied.

 

[drteeth]

I can hopefully give some more meaning to this answer:

For the d subshell, l = 2. ml =5 (b.c. from l, you get -2,-1,0,1,2). Thus the d subshell contains 5 possible orbitals each of which can fit 2 electrons. Hunds rule says that the orbitals will either want all unpaired electrons in each of these 5 orbitals or all paired electrons. Thus to have all unpaired you would need 5 electrons. Something like Cr has only 4 electrons and one unfilled orbital which means that its gonna snatch that electron from the s orbital and add it to its unfilled 5th orbital. Cu has 9 electrons which means that 4 will be paired but that the 5th orbital will have one unpaired. To be more stable it too will snatch that electron from the s orbital and add it to its 5th orbital to give 5 fully paired orbitals and 10 total electrons.

Hope this helps!

 

[Jo07]

😎 Thanks!