May 06, 2021, 11:45:23 AM
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Topic: Why is the electron config for Rn: [Xe] 4f14 5d10 6s2 6p6 and not..  (Read 2766 times)

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Offline Bbrow

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Rn: [Xe] 4f15 5d10 6s2 6p6?

I count 15 elements in the f sub-level, not 14

Is La counted as part of the d sub-level as it's config is: [Xe] 5d1 6s2


But why is it in the f?  ???

Offline mjc123

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Rn: [Xe] 4f15 5d10 6s2 6p6?
That would just be the wrong number of electrons. You can only fit 14 into 4f.
La has 4f0, Lu has 4f14.
Periodic tables vary; some have La below Y (in the d block) with Ce-Lu separate, as the f block, while some have La-Yb separate, with Lu below Y (then all the 3rd row transition metals have 4f14). Some, like www.ptable.com, have La-Lu separate, illogically suggesting a 15-element f block. I prefer the first style.

Offline Bbrow

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Quote
Rn: [Xe] 4f15 5d10 6s2 6p6?
That would just be the wrong number of electrons. You can only fit 14 into 4f.
La has 4f0, Lu has 4f14.
Periodic tables vary; some have La below Y (in the d block) with Ce-Lu separate, as the f block, while some have La-Yb separate, with Lu below Y (then all the 3rd row transition metals have 4f14). Some, like www.ptable.com, have La-Lu separate, illogically suggesting a 15-element f block. I prefer the first style.


I prefer the first style too, makes more sense for figuring out electron configurations - thanks for your help

Coincedentally,  I just found this article which shed some light on the matter (npi) too:
https://lavelle.chem.ucla.edu/wp-content/supporting-files/Publications/Lavelle_LaAc_in_d_Block_JCE2008p1482.pdf


Offline mjc123

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Thanks for that article; I entirely agree with the arguments.

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