Chemistry Stack Exchange
Chemistry Stack Exchange

Questions tagged [electronic-configuration]

In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

Knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements. The concept is also useful for describing the chemical bonds that hold atoms together. In bulk materials, this same idea helps explain the peculiar properties of lasers and semiconductors.

577 questions
18
votes
3 answers

Anomalous electronic configuration of platinum

Why is the electronic configuration of platinum $$\mathrm{[Xe] 4f^{14} 5d^9 6s^1}$$ and not $\mathrm{[Xe] 4f^{14} 5d^{10} 6s^0}$ or $\mathrm{[Xe] 4f^{14} 5d^8 6s^2}$?
lambda23
  • 2,510
  • 6
  • 29
  • 40
10
votes
1 answer

How are electronic configurations determined experimentally?

Despite the ubiquitous usefulness of electronic configurations (of elements) in explaining their behavious I have not been able to find out exactly how the configurations are determined. Is there any sure-fire technique to detect them (like x-ray…
Gerard
  • 3,441
  • 16
  • 38
  • 49
8
votes
2 answers

Why is it that energy of electrons in higher orbits is greater than the ones in lower orbits?

There is this picture I found online which indicates that the energy level is higher as we go up and more electrons are added to the atom. What I'm having trouble understanding is why the energy level is higher and not lower. The electrons are…
John Katsantas
  • 217
  • 2
  • 5
7
votes
1 answer

Reasoning for why anions have larger radius

I understand one thread of logic that adding electrons to create an anion creates more electron repulsion hence increasing the ionic radius. What's wrong with the reasoning that there is now a larger negative charge and hence the positive nucleus…
user54689
  • 91
  • 2
6
votes
1 answer

Are there no d-electrons in calcium?

For calcium, the electron configuration is $\mathrm{1s^2\:2s^2\:2p^6\:3s^2\:3p^6\:4s^2}$. Does it mean there's no electron in d sub-shell? Also, how would one write the electron configuration for a calcium ion?
Q.MEO
  • 321
  • 4
  • 6
  • 11
6
votes
2 answers

Orbitals and Pauli Exclusion Principle without Slater determinants

I'm trying to understand how to apply the pauli exclusion principle to the Born-Oppenheimer approximation of molecular structure. Let me preface this by saying I'm not a chemist nor physicist. I'm a mathematician by trade which has the side affect…
roro
  • 173
  • 3
6
votes
2 answers

Free radicals vs Hund's rule contradiction?

How do we reconcile these two statements? Formation of electron pairs is energetically favorable. Therefore, free radicals are particularly reactive Hund's rule - it takes energy to pair electrons, so orbitals are typically filled singly first
Jon Wilcox
  • 91
  • 1
6
votes
1 answer

What is the difference between the KLMN and SPDF methods of finding electronic configuration?

I've always been puzzled by this because my teachers happen to use only the KLMN method, but what is the difference between the KLMN and SPDF methods of finding electronic configuration?
Madhav Sudarshan
  • 163
  • 1
  • 1
  • 5
5
votes
1 answer

Is the electron configuration redundant?

For example the electron configuration for oxygen is 1s2 2s2 2p4. But if an element can never have an element in the p orbital unless it has 2 full s orbitals*, then why can't we write 2p4 as the electron configuration for oxygen? Is it not implied…
TAAPSogeking
  • 161
  • 4
5
votes
4 answers

Why exactly does atomic radius increase down a group?

I realize this should be a fairly basic question, but I'm still not quite satisfied with what I've been told from numerous sources. The general explanation seems to state that as we go down a group, there are more electron shells present to…
Nick
  • 343
  • 1
  • 5
  • 9
5
votes
3 answers

In which cases does the 3d subshell take precedence over the 4s subshell?

I've learnt in Chemistry that for example in Chromium, the 4s subshell only has one electron in favor of making the 3d subshell half-full. Also, for Copper the same happens. What other circumstances does this happen under? Do ions obey the same…
DarkLightA
  • 547
  • 1
  • 6
  • 13
4
votes
1 answer

Electron configuration of indium cation

Just had a lecture there where the lecturer was doing revision on electronic configuration. He stated that the electronic configuration of $$\ce{In^3+=[Kr] 5s^2 3p^1}$$ He didn't include the $\ce{4d^10}$ orbital. He said it doesn't matter and if we…
Patrick Moloney
  • 708
  • 1
  • 8
  • 20
4
votes
2 answers

Electron orbital diagram of vanadium

I am learning about electron configurations and I came across the "exceptions" of $\ce{Cr}$ and $\ce{Cu}$ where electrons actually half fill the $\mathrm d$ orbitals instead of the expected $\mathrm s$ orbitals. I thought maybe vanadium would do the…
Blargian
  • 227
  • 1
  • 5
  • 11
4
votes
0 answers

Some abnormalities in the Periodic Table

I observe some elements like $\ce{Cr}$ and $\ce{Cu}$. Some of them have strange oxidation numbers that don't really fit the purpose of making the element as stable as possible. Just Chromium, for example, it has one valence electron in 4s, the…
most venerable sir
  • 2,680
  • 13
  • 40
  • 65
3
votes
1 answer

What is an intuitive explanation for Electron Configurations

I'm sort of self studying Chemistry. I'm now getting stuck wrapping my head around a concept (and I realize it was the same concept I had difficulty grasping years ago) and that is Electron Configurations. I know that perhaps due to the nature of…
Secret
  • 141
  • 4
1
2 3 4 5 6