[vhpk]

I want to ask why Pd  has the configuration 4d¹⁰5s⁰

[Mitch]

Why do you think?

[vhpk]

I think perhaps this change is caused for better energy but when I see the elements over and beneath Pd, I can't find the similar , and I can't explain by any other energic reason.
Can you help me

[P]

4d10,5s0 is more stable than 4d8,5s2  so the electrons 'choose' to fill the d orbital completely rather than filling the s orbital and leaving the d partially filled.

[Dan]

4d10,5s0 is more stable than 4d8,5s2  so the electrons 'choose' to fill the d orbital completely rather than filling the s orbital and leaving the d partially filled.

This is implied by the question. The question is why is 4d10 more stable than 4d8 5s2?

[tortoise]

just a simply question, isn't it? 

[swap]

4d10,5s0 is more stable than 4d8,5s2  so the electrons 'choose' to fill the d orbital completely rather than filling the s orbital and leaving the d partially filled.

This is implied by the question. The question is why is 4d10 more stable than 4d8 5s2?

Because if you want to get 4d8,5s2 from 4d10 you should give energy to atom.However, with less energy atoms become more stable.So the electrons choose 4d10 form;less energy,more stable.It's The Aufbau principle (also Aufbau rule or building-up principle)

You can also think it like this:
You have an electron and a proton and the proton is fixed.The proton and the electron force each other to get closer.If you want to get them away from each other,you should force them in different directions.With E=F.x you can calculate the energy that you give the system.The electron gets farther.That makes the atom less stable because the atom have more energy.It should get it's former position and give the energy out to become more stable.

if there is a mistake, correct it please...

[P]

4d10,5s0 is more stable than 4d8,5s2  so the electrons 'choose' to fill the d orbital completely rather than filling the s orbital and leaving the d partially filled.

This is implied by the question. The question is why is 4d10 more stable than 4d8 5s2?

Being pedantic - the 'question' or the statement made initially is non senscical.  'I want to why Pd has...'   the sentance acually has no meaning and implies nothing.

[Yggdrasil]

One thing that doesn't make too much sense is why the stability of a completely full s shell gets traded for the stability of a completely full d shell.  For example, this phenomena does not occur in the case of nickel whose valence electron configuration is 4s²3d⁸.

[vhpk]

If you say the change is to make the stability, you can see Ni with the configuration 3d⁸4s² over Pd and Pt 4f¹⁴5d⁹6s², they don't change electron from subshell s to subshell d.

[vhpk]

Can you show your ideas, plz

[constant thinker]

Pt's electron configuration is...
[Xe]6s¹4f¹⁴5d⁹.
Ni is [Ar]4s²3d⁸
Pd is [Kr]4d¹⁰.
(for comparison)

I think it just may be an exception on the periodic table, and is an as of yet unexplained phenomenon why it's more stable that way.

Anybody can gladly correct me if they have any good thoughts or knowledge on the subject.

[Ψ×Ψ]

Because it's MAGIC! 
--$0.02 from an organic chemist who likes Pd-catalyzed reactions

[Mitch]

You can develop a rather competent explanation using circular reasoning from knowing the electron configuration of Pd in relation to other members of its group.

[enahs]

The anomaly is properly accounted for in Quantum mechanics. More specifically in regards to the Hartree-Fock method of approximation. That would be the simplest method to try and understand it, but to understand more then then equation(s) (which still takes advanced math skill to understand and work) requires comprehensive knowledge of quantum mechanics.


In short, the electron-electron repulsive forces in the d orbitals are greater then the electron-electron repulsive forces in the s-orbitals. Only in certain occasions when electron spin is being paired is it energetically favorable to "promote" the electrons. It happens to work out for Palladium, with its atomic size, effective nuclear charge, electronegativity, etc etc is the magnitude of the d electron-electron repulsive forces less than then magnitude of the differences in the orbitals.

If you want to know more become a physical chemist.

Point of interest, this is inconsequential. There are many mathematically predicted, and just as likely electronic configurations for the other elements that varies from the traditional values reported in the table. It does not really effect the chemistry, it is however have great importance when dealing with spectroscopy.