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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23
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4answers
29k views

Why does the energy gap for π - π* transitions shrink with the size of the pi-conjugated system?

Quoting from this site: As conjugated pi systems become larger, the energy gap for a π - π* transition becomes increasingly narrow, and the wavelength of light absorbed correspondingly becomes ...
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3answers
1.1m views

What are the maximum number of electrons in each shell?

In my textbook, it says that the maximum number of electrons that can fit in any given shell is given by 2n². This would mean 2 electrons could fit in the first shell, 8 could fit in the second shell, ...
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Why does the 3rd electron shell start filling up with scandium?

The electron configuration of calcium is 2, 8, 8, 2, where up to that point each shell, asides from the first shell counts up to 8 - why then does scandium have an electron configuration of 2, 8, 9, 2?...
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2answers
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Where does the 9th electron go in a N=O bond?

In the first resonating structure you can see 5 unpaired electrons and 4 shared electrons on nitrogen, then isn't this a extended octet? If it is so, then in which orbital that 9th electron is ...
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2answers
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Electronic configuration of tellurium

Below is a copy of the method I am using to determine electron configurations. Question: Write the full and short electron configuration for tellurium. My final answer was: Full Configuration: ...
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1answer
491 views

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 ...
3
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1answer
952 views

Configuration Interaction matrix composition from electronic configurations

The six electronic configurations below could all be found in the matrix elements of the CI matrix at CISD level. How do I construct the 6 x 6 CI matrix composed of these six configurations and which ...
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1answer
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Explaining the oxidation states of palladium

Palladium follows an exception to normal electron filling-up rules and so has the electron configuration of $\ce{[Kr] 4d^{10} 5s^0}$ The oxidation states of palladium are $\ce{+II}$ and $\ce{+IV}$. ...
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1answer
897 views

Plutonium having more oxidation states than samarium?

Why does plutonium have more oxidation states than samarium? Electron configuration of Pu: $\ce{[Rn] 5f^6 7s^2}$ Electron configuration of Sm: $\ce{[Xe] 4f^6 6s^2}$ I thought that only the valence ...
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1answer
530 views

Why is the ionization enthalpy of francium greater than that of cesium?

Why is the ionization enthalpy of francium greater than that of cesium, even though it has a larger size? I found no Google result regarding this.
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2answers
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Why does ammonia have sp hybridization?

Apparently it has $sp^3$ hybridization, but I don't understand why. Ammonia ($\ce{NH3}$) seems to me to not require $sp$ hybridization because all of its bond lengths are already equal. It has 3 ...
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1answer
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Does the hybridization model gives us any further insight on Molecular Geometry?

It doesn't seem as though the hybridization model adds anything useful to the discussion of molecular geometry as predicted by the VSEPR model. It's just another way of labeling linear, trigonal ...
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1answer
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How to compute the electron configuration of an atom?

How to compute the electron configuration of an (electrically neutral) atom ? So when given the atom number how does one compute the electron configuration ? I know the sum of electrons must equal ...
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1answer
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what is a difference between outer electrons and unpaired electrons

I know outer electrons include (n-1)d...+ all n'ss.. But i don't understand, never been told what unpaired electron is supposed to be? is it the same thing. so in the following electron configuration:...
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1answer
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Memorize Transition Metal Electronic Ground State

In the course of my undergraduate studies it has become clearer and clearer that it is quite helpful to know the ground electronic state of transition metals by heart, if only to speed up the process ...
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Have there been no advances in the determination of effective nuclear charges since Clementi and Raimondi in the 60s?

Effective nuclear charge is a very important concept in chemistry, and is the basis for the qualitative explanation of many observed chemical and physical properties, including several periodic trends....
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How can I figure out the electron configuration of Br-? [closed]

It's easy to do atomic electron configuration, but ionic is confusing.
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Is ionic bond just formed by “electrostatic” interaction between two oppositely charged ions?

According to the definition of ionic bond: An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. If we consider the above ...
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0answers
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Difference between inorganic and organic semiconductors: electronic structure or configuration, or?

Organic semiconductors differ from inorganic semiconductors. In organic semiconductors the molecules are held together by weak van der Waals interactions and in inorganic semiconductors by covalent ...
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1answer
351 views

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 ...
5
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4answers
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The violation of a certain rule or principle in the following electronic configuration

I'm to find the violation of a certain rule or principle in the following electronic configuration: $$\ce{1s^2 2s^2 2p^1_x 2p^0_y 2p^0_z}$$ $n+l$ rule is not violated because: for $\ce{1s^2}$, $n+l=...
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1answer
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Number of pi-electrons in an energy state

I am learning quantum chemistry and I am trying to understand the statement in a .pdf I'm reading which states "The energy transition associated with the spectral transitions observed is: $$\Delta E = ...
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Lone pair electrons on secondary carbon vs primary carbon

I know that a molecule is more stable when a free radical is on a secondary carbon over a primary carbon, but how about when there is a lone pair of elections that can be placed on a secondary or ...
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1answer
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Why apart from when building atoms in the first place, the 3d is the lower energy orbital?

From chemguide.co.uk: If the phosphorus is going to form $\ce{PCl5}$ it has first to generate 5 unpaired electrons. It does this by promoting one of the electrons in the $\mathrm{3s}$ orbital to ...
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1answer
947 views

What is the number of lone pairs of central atom when it has an odd number of electrons?

What does it mean in asking the number of lone pairs of central atom when it has an odd number of electrons? As lone pairs means the no. of non bonding pairs of electrons does it exclude the one odd ...
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1answer
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What is the right quantum numbers of Copper?

Copper have $[Ar] 3d^{10} 4s^1$ electron configuration. And Zinc have $[Ar] 3d^{10} 4s^2$ electron configuration. My question is, what is the right quantum numbers of last electron of copper? Is it $$...
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1answer
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What makes Gold so different from Platinum? [closed]

Looking at Wikipedia, Gold & Platinum are in adjacent seats. ...
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1answer
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Special electron configurations in p block on periodic table?

Gold and Chromium have weird electron configurations, because electrons are differently divided : eg an electron jumps from a s-orbital to a d-orbital to have a half-filled s orbital and a fully/half ...
4
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1answer
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Finding electron configuration of lanthanide ions

When I have a gadolinium ion ($\ce{Gd^3+}$), how can I calculate its electron configuration? $$\ce{Gd} : \mathrm{[Xe] (4f)^7 (5d)^1 (6s)^2}$$ Do I need to first subtract the 2 electrons in the $\...
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2answers
301 views

Do ions also form special electron configurations? (just as Copper and Chromium do)

Do ions also form special electron configurations? (just as Copper and Chromium do) I know that because copper has 1 electron in its s-orbital (highest) because it wants to have a full d-orbital (d^...
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Negative charge of methoxide anion

Why is the methoxide ($\ce{CH_{3}O^{-}}$) anion negatively charged? It has 13 valence electrons and has 13 free electrons. In spite of that the methoxide anion is negatively charged.
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Valence electrons in helium?

I am having trouble understanding how valence electrons are counted in Helium. My references are: Here where it appears that Helium has 0 valence electrons because the shells are finished Here ...
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615 views

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 ...
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2answers
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Why does oxygen not like to be a double anion?

The electron affinity of a neutral oxygen atom is −142 kJ (it releases this energy). The electron affinity for the now double anion $\ce{O^2-}$ is 710 kJ (work must be done on the atom). My question ...
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2answers
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Anomalous electronic configurations

Cu has an anomalous electron configuration. $\ce{Cu ~=~ 1s^2~2s^2~2p^6~3s^2~3p^6~4s^1~3d^{10}}$, it does not follow the usual pattern. In this case, the 3d subshell is filled before the 4s, which ...
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1answer
105 views

Why is there a max radius for an orbit of an electron around a nucleus?

Why is there a max radius for an orbit of an electron around a nucleus ? I had a course in electromagnetism but I do not get this.
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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 $\mathrm{[Xe] 4f^{14} 5d^8 6s^2}$?
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2answers
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If copper has 2 valance electrons and sulfur 6, why don't they bind in pairs?

Simple question, the average neutral copper atom has 2 valance electrons, and sulfur 6. Wouldn't the two electrons jump from copper and bind to sulfide? The empirical formula is: $\ce{Cu + S -> ...
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4answers
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How can one explain niobium’s weird electronic configuration?

As cited in an answer to this question, the ground state electronic configuration of niobium is: $\ce{Nb: [Kr] 5s^1 4d^4}$ Why is that so? What factors stabilize this configuration, compared to ...
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1answer
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Is the half-full rule and full rule followed in the 6th and 7th periods?

Is the half-full rule and full rule followed in the 6th and 7th periods? (Note: Half-full rules is Hund's rule) Example: What is the correct electron configuration? $$\ce{W = [Xe] 6s^2 4f^{14} 5d^4}$$...
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1answer
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What determines the electronegativity of an element?

Is it possible to work out without post-Bohrian mathematics?
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1answer
842 views

Lewis dot structures and exceeding the octet

I'm confused about the octet rule. As far as I understand, you need to complete the valence shell of the elements by sharing electrons. Now, carbon has 6 electrons which means it has 4 valence ...
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Is the order of orientation of electron box diagrams meaningful or arbitrary?

Here is my interpretation when asked to: By drawing arrows in the appropriate boxes, complete the outer electron structures for Cu and Cu2+ I had no problem in drawing out the electron structure, ...
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Can an atom have more than 8 valence electrons? If not, why is 8 the limit?

According to some chemistry textbooks, the maximum number of valence electrons for an atom is 8, but the reason for this is not explained. So, can an atom have more than 8 valence electrons? If ...
21
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1answer
493 views

Is the Springborg 6D phase space model used in modern molecular orbital modeling?

In a series of papers in the early 1980s, Michael Springborg explored an interpretation of the Wigner phase space function as an electron density in a six-dimensional $(q,p)$ phase space. He applied ...
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Are there any major exceptions when comparing electron affinity?

I was tasked with figuring out whether carbon or nitrogen has a more negative electron affinity value. I initially picked nitrogen, just because nitrogen has a higher $Z_\mathrm{eff}$, creating a ...
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Why do elements in columns 6 and 11 assume 'abnormal' electron configurations?

When I look around for why copper and chromium only have one electron in their outermost s orbital and 5/10 in their outermost d orbital, I'm bombarded with the fact that they are more stable with a ...
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1answer
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Why is the vanadium(3+) ion paramagnetic?

I know that the electron configuration of vanadium is $[\ce{Ar}]\mathrm{4s^2 3d^3}$. None of the electrons in the 3d subshell are paired. Once it loses these three electrons, shouldn't the remainder ...

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