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.
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Why do some elements exhibit variable valency?
I searched across the internet and the only answers I found were that it is due to the inert pair effect or due to energy difference between orbitals. Now since Auf-Bau principle is used to write the ...
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Non-octet structures of stable nitrogen compounds
A question in my exercise book demonstrates that nitrogen cannot form non-octet structures since the most common examples — nitrogen dioxide and nitrogen monoxide — are unstable/reactive. For example, ...
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Radius of Ag+ and K+
According to the database of ionic radius
Database of ionic radius
The ionic radius of silver(I) cation is totally smaller than potassium(I), regardless of their coordination number.
It seems quite ...
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When relaxing the strong field interaction, the (t2g)^2 configuration splits into 4 states. What is the symbolic configuration of the Eg state?
When relaxing the infinitely strong field, the electrons start to feel one another's presence. They will, therefore, give rise to sets of states such as T1g, T2g... for the (t2g)^2 initial ...
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How does Platinum attains more stability in config: 5d9 6s1 then config: 5d8 6s2?
According to Aufbau's Rule, It must be 5d8 6s2..
Even if considering stability; In terms of exchange energy and pairing, 5d9 has only 1 free electron, and thus no exchanges are possible as all other 4 ...
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Convergence limit of emission spectra for atoms with multiple electrons
In high school chemistry, students are taught that the convergence limit in the emission spectrum of an element can be used to determine the first ionization energy.
However, what about the second, ...
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Eigenfunctions of total angular momenta as linear combinations of Slater-determinants
In the Hartree scheme for many-electron atoms, the approximated Hamiltonian (in a.u.)
$$\hat{H} = \sum_{i=1}^Z \left(-\frac{1}{2} \nabla_i^2 -\frac{Z}{r_i} + V_\text{H}\left(r_i\right)\right)$$
is ...
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Principal quantum number and 'good' quantum numbers
When we discuss about configurations we specify n, l, m quantum numbers for the individual electrons.
My question is: why when we pass from configurations to atomic terms in order to use the total ...
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Why is iron(III) more stable than iron(II)?
What I have seen, and what has been answered before (Why Fe 3+ is more common than Fe 2+), is that it is due to the half filled d orbital of $\ce{Fe^3+}$ compared to $\ce{Fe^2+}$. I don't understand ...
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D block elements and the cation of cobalt [closed]
The configuration of cobalt in its ground state is $\ce{[Ar] 4s^2 3d^7}$. when it loses 2 electrons, it supposedly leaves from s orbital making it $\ce{[Ar] 4s^0 3d^7}$. But since the s and d orbital ...
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Why is there a non-uniformity in even the reasons that explain exceptions in the trends in chemistry? [closed]
I have been studying the periodic table and several properties of atoms like the Ionization Energy, Atomic Radii, Electron gain enthalpy, Electronegativity etc.
Now, each property has somewhat of a &...
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Confusion about the number of microstates for orbitals
I am very confused about the microstates for a specific orbital.
Let's suppose I have an electronic configuration
$$
\ce{[\dots] 2p^5}
$$
Considering the symmetry of the orbitals and the "...
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Why is nucleus coupling neglected to explain electronic states but LS coupling only rises because of?
Here, with LS coupling I mean coupling between total orbital momenta and S total spin momenta and treating eletrons in light atoms with Russell-Saunders approximation. I found a bit paradoxical that ...
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What does it mean when there is a term in parenthesis in an electronic configuration?
This may be a silly question, but I have not yet found an answer and I don't really know how to word my searches. I have been looking at the NIST Atomic Spectra Database (and also atomic physics ...
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How many m values are there for the 4f sublevel. In high school so no fancy words please! [closed]
How many m values are there for the 4f sublevel? In high school so no fancy words please!
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1H-NMR: What parameters influence spin-spin coupling between protons, and why?
I'd like to better understand spin-spin coupling. What other mechanisms are there besides fermi contact interactions? How are the different mechanisms influenced by different parameters like ...
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How can one obtain the same-spin and opposite-spin terms of the MP2 energy by integrating out the spin?
Just as specified on the psi4 website here: https://psicode.org/psi4manual/master/dfmp2.html, the Moller-Plesset Perturbation Theory states that the second order correction to the ground state energy, ...
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Why does XeO3 not hybridize d orbitals? [duplicate]
Apologies if this is a dumb question. In my chemistry class we are discussing hybridization, and an example that came up for $sp_3$ hybridization was the compound $\ce{XeO3}$.
However, this seems ...
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LCAO-MO ansatz for arbitrary hydrogenic molecule term
I am struggling to understand the connection between molecular electronic term symbols and translating the symmetries to the underlying wavefunction.
In particular, my understanding of the LCAO-MO ...
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On the energies of molecular orbitals
I found a useful (though simplified) scheme illustrating the energies of atomic orbitals, in crescent order:
I wonder if there was an analogous (simplified) scheme or rule for molecular orbitals, at ...
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Which one has higher priority in CIP rules -- O or OH?
I know that if the atom is the same, I have to look at the next atom. In the first choice, Oxygen is not connected to any other atom (besides the chiral carbon). It is an anion. Whereas in the second ...
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What determines the higher priority in CIP rules, if both groups have the same atoms?
Which of the following groups has the highest priority in the Cahn-Ingold-Prelog sequence rules?
a) CH2CH3
b) CH=CH2
c) C≡CH
d) C(CH3)3
I narrowed it down to either C or D. The carbon in answer C is ...
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sp mixing in $N_2$ vs sp mixing in CO
We were first taught that in B, C and N the bonding $\sigma_{2s}$ orbital repels with the bonding $\sigma_{2p}$ orbital which cause the energy level of $\sigma_{2p}$ orbital to increase. This increase ...
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How can Planck’s equation and the wave equation simultaneously coexist with contradicting each other? [closed]
The equations:
E=hf (Planck’s equation, where E is the energy, h is the Planck’s constant and f is the frequency) and
V=fλ (where v is the speed (in a vacuum), f is frequency and λ is the wavelength) ...
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Hartree Fock calculations on F2 don't match the traditionally taught MO diagram
I ran some Hartree-Fock calculations on F2 to visualize the MOs, and the energy levels don't match the trend commonly taught (shown here: https://chem.libretexts.org/Courses/...
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Why is the d subshell only stable when all of its orbitals are filled? [closed]
I was learning about the Aufbau principle and quantum electronic configuration. Here are some of the yet-unanswered queries that I wish to know the answers to.
I discovered that the d subshell is ...
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Why does berkelium have two electronic configurations?
J.D. Lee Concise Inorganic Chemistry, Appendix E: Electronic Structures of the Elements [1, p. 601] provides two electronic configurations for berkelium:
$$
\ce{Bk}\quad
\begin{cases}
[\ce{Rn}]~\...
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How does bond formation affect the energetics of the bond?
I am an 11th grade student who has just started learning about bonds in compounds. My question pertains to a line written in JD Lee's Concise Inorganic Chemistry for JEE (Main and Advanced)
It was ...
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Why silicon doesn't have the electronic configuration [Ne] 3s¹ 3p³?
I have read that half or fully filled orbitals provide more stability to the element due to symmetry and exchange energy.It is the reason for electronic configuration of Cr-[Ar]4s¹3d⁵.
Then, why doesn'...
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Electronic configuration of Cu⁺ and Cu²⁺ [duplicate]
I understand that copper has the electronic configuration $\ce{[Ar] 4s^1 3d^10}$ because a fully filled $\ce{4d}$ orbital provide a more stable configuration.
But I don't understand why the two copper ...
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What is the energy difference between inner subshells?
For exemple, in silver the energy difference between the 4d 5s subshells is ≈ 4 eV (in the ultraviolet region, that's why it has no color, etc.), but what is the energy difference between some of its ...
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Why does lead gains electrons in the cathode? [closed]
In lead(II) bromide electrolysis, lead is attracted to the cathode and gains electrons. Why does it gain electrons when losing them would be easier since its charge is +2 meaning it would need to lose ...
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Analog of chemical accuracy in vibronic energy calculation [closed]
Is there any analog of chemical accuracy in vibronic energy calculation? I understand that the unit is /cm however, probably, I shouldn't expect a given number in that unit as the analog.
I am ...
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Why are there so many metals in the periodic table?
Brief Background: I was studying about the 'classical electronic configuration' of the first 20 elements of the periodic table today and was bewildered by the fact that there are an equal number of ...
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Why the electronic configuration of samarium is ending with 4f⁶6s²
What is coming in my mind is that 4f^7 6s^1 should be more stable as it allows two orbitals to be half filled rather than 4f^6 6s^2 in which only one orbital is completely filled....can someone please ...
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Electronic configuration in d-block
According to Bohr-Bury rule, 4f and 5d orbital come after 6s orbital. But if I search for the electronic configuration for Os or any atom in d block for that matter, they give the electronic ...
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where could I find the standard atomic orbital energy of all elements?
I am trying to find the standard atomic orbital energy of all elements.
Here is the data I found in some old books:
I am looking for some more modernized data, I tried to look for the data in the CRC ...
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Fundamental doubts about energy levels vs. shells vs. subshells vs. orbitals
First in school I learnt that when supplied enough energy, the electron in a hydrogen atom will jump energy level(s), denoted by $n=1$, $n=2$ and so on for integral values of $n$. Then I learnt about ...
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Are there any monocations with negative electron affinities known?
It is known that most dianions are unbound per se, i.e. that the corresponding monoanions have negative electron affinities, and the "dianions" we see in e.g. metal oxides can exist as such ...
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Why does symmetrical distribution of electrons in d and f orbital lead to greate stability of these or orbitals in comparison to s orbital? [closed]
My high school textbook mentions the following as on of the reason for why Cr and Cu have thier 3d orbitals filled completely before their 4s orbital.
The extra stability of d and f orbital is due to:...
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Do diatomic isoelectronic molecules have the same bond order even when the octet rule is not followed?
It can be observed and proven that diatomic isoelectronic molecules have the same bond order when they follow the octet rule (upto 3rd period elements). But what about when they do not follow the ...
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Why is it wrong to draw the Lewis structure of a molecule's atoms and then figure out the Lewis structure of that molecule
When drawing for example the Lewis structure of nitrate ion (NO3)^-1 whould it be wrong to draw nitrogen and oxygen separately and then try to figure out the structure of the ion? In that case does ...
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How do the spin-matrices change in systems without spherical symmetry?
The (non-relativistic) spin matrices of a free electron, with $z$ as the quantization axis, read:
$$
\boldsymbol{S}_{x}=\frac{\hbar}{2}\left[\begin{array}{ll}
0 & 1 \\
1 & 0
\end{array}\right],...
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How to obtain excited state energies from configuration interaction? (Helium example)
A theory of CI method
For going beyond the Hartree–Fock (one determinant) approximation one introduce configuration interaction (CI). Interaction means the mixing (interaction) of different electronic ...
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Hund's Rule for Determining Term Symbol Energy Order
In order to determine the energy order based on J-value for term symbols we employ Hund's rule:
In a less than $\frac12$-filled subshell Lowest J-value is Lowest energy
In a more than $\frac12$-...
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Electronic vibrational rotational transition of electrons -- for a transition from $\Sigma$ to $\Pi$ how are P and R branches possible?
Suppose we have a diatomic molecule in a $^1\Sigma$ state, and it transitions to an excited $^1\Pi$ state. Note that the total spin of the electrons remains unchanged ($\Delta S=0$) as we can assume ...
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Can there be a molecule where every atom is covalently bonded to every other atom? [closed]
I was wondering if muliple atoms could bond in a ring, but share a pair of electrons with every other atom in the molecule so that every atom is connected to every other atom. Would it be possible for ...
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A question regarding excitation of electrons in atomic orbital [closed]
In Bohr's model of an atom, the formula used to find the energy between the 2 orbits and wavelength of emitted photon was valid only for single electron species like hydrogen.In the case of a multi-...
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Can halogens show -3 or -5 or -7 oxidation state. Why? [closed]
I mean can we think it like if the electrons get excited into the d orbitals and because there are now more than one unpaired electron, why does it only loose them and why don't they accept more than ...
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In Lanthanides, Why is electron removed from 4f before 5p? [duplicate]
I've been taught that electrons are removed first from valence shell electrons with highest energy. But In Lanthanides, for example taking configuration- [Xe]4f⁴6s², If we go to +3 Oxidation State, ...
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