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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Josette017 on December 09, 2007, 12:25:45 PM

Title: Orbital Diagram & Electron Configuration
Post by: Josette017 on December 09, 2007, 12:25:45 PM
The following problem is in my Chemistry book...

Write the orbital diagram corresponding to the ground state of Nb, whose configuration is [Kr]4d45s1.

I look at this and find Nb's configuration to be [Kr] 5s24d3.

Am I wrong about this or is the book wrong?      ???


Thank you for your help
Title: Re: Orbital Diagram & Electron Configuration
Post by: lost and found on December 09, 2007, 04:41:21 PM
My sources say that the book is right  :)

Nb = [Kr]4d45s
Title: Re: Orbital Diagram & Electron Configuration
Post by: champ on December 09, 2007, 05:38:46 PM
the book is right because block "d" elements lose block "s" electrons first. so thats why the configration of Nb is
Nb = [Kr]4d45s
Title: Re: Orbital Diagram & Electron Configuration
Post by: agrobert on December 09, 2007, 05:46:03 PM
Quote from: champ on December 09, 2007, 05:38:46 PM
the book is right because block "d" elements lose block "s" electrons first. so thats why the configration of Nb is
Nb = [Kr]4d45s
Not exactly

http://en.wikipedia.org/wiki/Electron_configuration#Exceptions_in_3d.2C_4d.2C_5d
Title: Re: Orbital Diagram & Electron Configuration
Post by: serdi on December 10, 2007, 02:34:54 PM
Why Nb 's configuration [Kr] 5s1 4d4 ? there is no half filled shell? I expected like [Kr] 5s2 4d3 as Josette?
Title: Re: Orbital Diagram & Electron Configuration
Post by: Borek on December 10, 2007, 03:47:03 PM
IMHO these are fineprints that are not worth looking at for exact explanation. Thing is, energy levels of these configurations are very close. We are comparing huge numbers (energy) that differs by small amount. Sometimes effect of half orbital being filled wins, sometimes effect of full oribital wins. For me looking for hard rules here is not worth much more then numerology. These are just excpetions and should be treated like ones.