Questions tagged [electrons]
Electrons are subatomic particles with the symbol e−. They have a negative electric charge (-1 elementary charge. )
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Inter electronic repulsion in s and d orbitals
This was written in a lecture slide:
Two electrons present in the same d-orbital repel each other more strongly than do two electrons in the same s-orbital.
Why is there a difference in the amount ...
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What exactly is an "electron-sponge"?
What exactly an "electron-sponge" [behavior/action/property/system] nickname is, and what makes a material an "electron-sponge" (preferably, quantitatively)?
From what I found, it's typically a ...
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Are there bonds which share single electron?
Are there bonds which share single electron?
During chemical bonding, I asked our teacher why there are only 2 electrons shared in a bond. He said that because it's that one orbital can accommodate ...
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Why do nuclei move considerably slower than electrons
I've been trying to learn quantum chemistry at an introductionary level. While reading I've found out that the Born-Oppenheimer approximation seems to be the reason for the basic and crucial model of ...
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Electron promotion in hybridisation: A misconception
Recently, I read through a short article on Nature Chemistry, written by Michelle Francl, titled "Talking to Pauling's ghost". The article talks about how electron promotion was never something that ...
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NO coordination linear vs bent - valence electron
I'd like to count the total valence electron of following neutral complex in the ionic counting (=donor-pair):
Electron count:
$$\begin{align} \ce{Cp-} : \ce{6e-} \\ \ce{CH3-}: \ce{2e-} \\ \ce{PPh3} :...
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Why does diamagnetic current induce a downfield while the paramagnetic current induces an upfield shift?
I know that aromatic rings exhibit diamagnetic ring currents which causes the protons outside the ring to go downfield in H-NMR. Antiaromatic compounds exhibit paramagnetic ring currents which have ...
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Did JJ Thomson know about Eugen Goldstein’s experiment discovering canal rays?
We learn that JJ Thomson discovered the electron in 1897. Several years EARLIER in 1886, Eugen Goldstein performs the same experiment but with the anode and cathode switched to produce positively ...
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Has a concept of temperature ever been defined in the context of a single atom?
I wonder if this answer to What would happen if we supercool and then superheat an atom very abruptly? goes far enough.
I almost wrote the comment:
I don't think we can even talk about the ...
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State symbol for electron
Is it correct to write a state symbol of "g" or "l" for an electron? In the textbook I am currently reading, the state symbol "g" was used for the electron when it described the electron gain by a ...
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Difference between change in energy level and hyperfine energy level?
The second is the duration of 9 192 631 770 periods of the radiation
corresponding to the transition between the two hyperfine levels of the
ground state of the cesium 133 atom.
--> This ...
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Is the surface electron affinity of (tribasic) sodium- or calcium phosphate higher?
Let's imagine we have two polycrystalline samples: $\ce{Ca3(PO4)2}$ and $\ce{Na3PO4}$. A free electron is added to both. Some heat is released.
I wanted to check whether my reasoning about this ...
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Is double excitation of nitrogen possible, and would it be able to use it as a central atom in a coordination complex?
I’m 17 and in my 2nd year of high-school (we have it a tad different here in the Czech Republic) and am interested in theoretical chemistry so that’s the explanation of the nature of my question.
So, ...
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Shielding vs electron-electron repulsion
Example of shielding:
(source)
The last electron in the 6s subshell of $\ce {Cs}$ is shielded from the nucleus by the inner electrons.
Example of electron-electron repulsion:
The electron affinity of ...
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Why is the bond angle of sulphur difluoride greater than that of hydrogen sulphide?
Why is the bond angle of $\ce{SF_2 (98.05^\circ) > SH_2 (92.11^\circ)}$?
Isn't this contradicting Bent's rule or otherwise electron repulsion rule ? Fluorine is more electronegative and hence it ...
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Do Hartree-Fock (or other model Hamiltonian) electron densities fullfill the Kato theorem?
I have done Hartree-Fock calculations on a single He atom and now I tried to check numerically if the electron density fulfills the Kato theorem. It apparently doesn't. Instead I obtain a cusp ...
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Confused about identifying delocalized electron pairs in Isoniazid
I have to identify delocalized electron pairs in Isoniazid (pairs not shown in the image below):
I know the nitrogen in the ring has a localized electron pair, since it already forms a pi bond. I'm ...
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how can I tell compton versus coherent scatter apart?
I am trying to get a better understanding of compton and coherent scatting, along with all the other interactions. It has seemed like a lot to memorize and I am trying to find ways to more easily ...
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Question about reaction in battery
I made a battery like this.
$\ce{(-)Al|HCl,CuSO4|Cu(+)}$
By piling up 6 battery of this(actually I made this using 10 yen and 1 yen coins:10yen coin is Cu and 1 yen coin is Al.) I could turn on an LED ...
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Magnetic moment of an electron not parallel to its angular momentum?
For the total angular momentum of an electron $\vec{J} = \vec{L} + \vec{S}$, we're often shown a picture like this
where I assume that the $\vec{L}$ and $\vec{S}$ cones are centred on the $J$ axis ...
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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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AlCl3 and water
While reading Clayden's (et al) Organic Chemistry I stumbled upon a reaction on page 120 that I just fail to wrap my brain around. It describes a reaction of AlCl3 with water and states that, quote, &...
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What will the correct value of spin quantum number for last electron of Na+ ion?
Electronic configuration of $Na^+$ ion is $1s^2,2s^2,2p^6,3s^0$.
I have noticed usually , we take spin quantum number as +1/2 first & then -1/2.
So , like for the above Q:It is for first 3e=+1/2 &...
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Number of π electrons in all trans-2,4,6-octatrienoic acid
Sketch the Lewis structure of all trans-2,4,6-octatrienoic acid.
(a) Consider the delocalized π electrons. Employ the particle-in-a-box model. Drawing on your knowledge about the occupation of ...
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Excitation states of neon (or other gas) inside neon lights
I'm interested in the spectra of gas discharge tubes.
Taking neon as an example, when I look up on NIST the spectra for neon, I find excitation states up to Ne IX. Where do I find/how do I work out ...
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Ionic radius for tetrahedral metal–ligand complexes
The ionic radii for metal–ligand complexes that are in an octahedral coordination are easy to find. I understand that when the $\mathrm{e_g}$ orbital is filled, the ionic radius increases because the ...
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Direction of electron density in p orbitals
$\mathrm{s}$ orbitals are spherically symmetric while $\mathrm{p}$ orbitals are not. For Boron, the electronic configuration is $\mathrm{1s^2 2s^2 2p^1}$.
In which p orbital does the most energetic ...
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Free Electron-Bond Electron Interactions
I am reading an introductory textbook on electronics: Practical Electronics for Inventors by Paul Scherz and Simon Monk. In a section discussing the motion of electrons in circuits, the textbook ...
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How are second and third electron affinities of atoms measured?
Wikipedia data page on electron affinities shows second and third electron affinities. Of course, they are negative, because one tries to attach electron to anion. But how are they measured or ...
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As an atom get's bigger (on increasing atomic no.) , electrons have to move faster and faster around the nucleus, Why?
Does speed even make sense at such small scales ? Heisenbergs Uncertainty principle ?
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Unpaired electrons from magnetic moment
A complex formulated as $\ce{Cs_x[NbCl6]}$ has spin-only magnetic moment $\mu_{s.o}$ of approximately 2 B.M. From this value calculate how many unpaired electrons are present.
Spin-only magnetic ...
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Is Effective Nuclear Charge the same as Core Electrons?
I'm wondering, what is the difference between the two?
Using the equation for Eff: $\ce{Zeff = Z - S}$
Z being the number of protons in the nucleus and S being inner-shell electrons.
For example:
...
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Does restriction on spin in orbits exist?
For a valence electron in Antimony (Sb) with the electron configuration:
$Kr(5s)^2(4d)^{10}(5p)^3$
The 3 valence electrons have the quantum numbers $n=5,l=1,m=1$, resulting in the following ...
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How would you find the expected molecular orbital energy diagram for compounds such as NO?
How would you find the expected molecular orbital energy diagram for $\ce{NO}$? Would it be the expected one for $\ce{O2}$? Or the one for $\ce{N2}$? Also, would the ionization energy be bigger than ...
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Nomenclature of This State?
I've read this in a book
It says the state having three parallel spin is called triplet state .
But as far as I know it is determined by "2S+1", from this it comes out to be 4 . Then how it is "...
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How to tell the needed doping element for semiconductors?
I was reading about a crystal that is a semiconductor, galena. I am confused on how to tell what elements are needed to dope it to make a p or n type semiconductor, as well as how to know which ...
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How to analysis the amount of reactive oxygen atom in specific molecules
From a Phd dissertation here, I read about the material follows:
"Odd oxygen is a measure of oxidative capacity of the atmosphere. It contains species with an oxygen atom avaliable to serve as ...
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Few basic questions about ionic bonding and batteries (lead)
I've got a few very very basic questions about ionic bonds and their role in batteries.
My assumptions (correct me if I'm wrong):
Ionic bonds occur between a metal and a non-metal (the non-metal ...
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Is there an algorithm for ascertaining the relative size of an atomic/ionic radius?
To the best of my knowledge, the following properties affect atomic radius.
The grounded-state size of the valence electron shell.
The Coulomb force of the core electrons less the Coulomb force of ...
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First ionization energy of hydrogen molecule
If we have the dissociation's energies of hydrogen molecule $\ce{H_{2}}$($D_{0}$) and the corresponding molecule ion $\ce{H_{2}^{+}}$ ($D_{1}$) together with the first energy of ionization of hydrogen ...
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Is Sodium metal more reactive towards an alkyl halide or an alcohol in a protic polar solvent?
Will Sodium metal donate its electrons to bromine in 1,3-dibromopropane or to the hydroxyl group in ethanol in a polar protic solvent?
This question comes from a problem:
'What is the major product ...
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Trends in conductivity in groups 1 and 2
I have read that the trend for conductivity in groups 1 and 2 is a decrease down the groups (generally). Apparently this is because the atoms of each element get larger, so while the number of ...
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Order of radical dimerization ability
In a question I came across recently, it was asked to arrange the following radicals in the ascending order of dimerization ability.
I have read about the triphenylmethyl radical undergoing Gomberg ...
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how to make a PEM (proton exchange membrane) out of Nafion Dispersions?
I would like to use a Nafion membrane for a fuel cell project, but the Nafion sheets are hard to integrate. Therefore, I would like a gel type of Nafion that can take the shape of the container I put ...
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What is the paramagnetic susceptibility of sodium at around room temperature?
Proposed solution:
This question comes from Tanner's manual Introduction to the Physics of Electrons in Solids, at the chapter dedicated to the application of the Fermi gas model. The Fermi energy is $...
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How do dielectric molecules in a liquid phase align when polarized?
As seen in the diagram, when a dielectric material becomes electrically polarized, the molecules align themselves in a manner where the respective charges are parallel to each other horizontally.
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Maximum number of Spectral Lines "A better quantum model shows that there will be n^2 transitions"?
I was parsing the following post What is the maximum number of emission lines when the excited electron of a H atom in n = 6 drops to ground state? and came across with the reply from @porphyrin.
cite ...
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Why does allyl anion have only two resonance structures?
There are only two resonance structures of allyl anion with negative charge distributed over positions 1 and 3:
$$\ce{\overset{-}{C}H2-CH=CH2 <-> CH_2=CH-\overset{-}{C}H2}.$$
What's the criteria ...
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Is the C-I bond polar?
Carbon and iodine have similar electronegativities. The reason quoted for the C-I bond having polarity is that iodine is more polarisable.
But what does this actually mean? Carbon distorts the ...
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Equilibrium cell potential question
In an attempt to wrap my head around the basics of electrochemistry I'm working my way through Wesley R. Browne's 'Electrochemistry' primer.
With regards to the equilibrium potential of an ...
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