Questions tagged [electrons]
Negatively charged particle with spin 1/2. A component of mundane terrestrial matter, and part of all neutral atoms and molecules. It has a mass about 1/1800 that of a proton. Its antiparticle is the positron.
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Electronic energy eigenstate
In the context of the hydrogen atom, the ground-state energy of the electron is $-13.6eV$. As the principal quantum number $n$ increases, the energy of the bound states approaches $0$.
$$
E = \frac{-...
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Why do electrons not pass through a screen?
Rutherford aimed alpha particles (helium nuclei) at a gold foil and found that most of them went right through and only a few bounced back. If we aim deuterium nuclei (deuterons) at a gold foil we ...
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Are angular momentum selection rules only understood for hydrogen like species?
I am someone with a rudimentary understanding of atomic and molecular physics, and with that I'm trying to understand in which case which selection rule becomes applicable. For the angular momentum ...
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How to understand whether an electron in an atom is in superposition, ground or excited state?
As I understand it, defining the orbital of an electron implies that it can be detected with a certain probability in a certain place. But if we take an atom and it is in a superposition state, then ...
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How did the first CRT monitors with Beam Penetration create a full set of colors?
Was reading about early CRT methods and came across the idea of Beam penetration, which from what I can tell was the first method of using these devices to make color images: two layers of phosphors ...
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Why does electron's orbital momentum have weaker magnetic field than the electron's spin momentum?
The orbital magnetic field is caused by electrons orbiting the atom. If I'm right the magnetic field of the spin is caused by larmor precession. Here I don't understand, why is magnetic field of spin, ...
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Why doesn't it require breaking a bond for a valence electron to fill a neighboring hole?
I am watching a lecture series on semiconductor physics on YouTube and I am at a point where the professor is explaining the concept of a hole and how bounded electrons (valence electrons of an atom ...
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What is the status of Wheeler’s ‘one-electron universe’ idea? [duplicate]
I'd like to ask the experts about the following:
Sometime ago, I read about the One-electron universe postulate by Wheeler, and I found the concept fascinating. I wonder if it is a line of work that ...
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Beta particles in Rutherford experiment
What happens if beta particles (electrons) are used in Rutherford gold foil experiment instead of alpha particles? Is there any possibility for the beta particles to be repelled by the existing ...
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Can electrons be in the nucleus if electrons and protons swap masses? [closed]
Is is more stable for nucleus to be made of protons?
What if the mass of electron and proton were swapped? will then the nucleus be made of negatively charged particles?
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What happens to an electron inside an uniform, time-varying magnetic field?
Suppose I have a really long coil with a current running through it, such that there's a pretty uniform magnetic field along the center axis. Now suppose I place a tiny charged particle, like an ...
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How do valence band electrons move within a semiconductor lattice?
I am currently reading the book Semiconductor Device Fundamentals by Robert F. Pierret. In the chapter on carrier modeling, he discusses the valence and conductance energy bands of a semiconductor ...
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Electron energy loss after collision with phonon
This paper considers the loss of energy when an electron scatters with a phonon. They write in Part C:
Assuming the phonon energy corresponds to the Debye temperature (
$\approx 0.03$ eV in Cu , and $...
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About how to express the movement of electrons along a conductor
I'm not an expert and have only a short knowledge of electron.
I was looking up the operating principle of lithium-ion batteries and there was something I didn't understand about the way it was ...
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How come Selenium's Seebeck Coefficient is higher than that of Tellurium?
A little heads up: I came across a Science Mag article on Thermoelectric Materials (Focus was on SnSe (tin selenide). Loved how it sort of spells "Sensei" - this is beside the point) today ...
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Energy below threshold energy in photoelectric effect
In the photoelectric effect we shine photons onto a metal surface and if the frequency is greater than some threshold frequency photoelectrons are emitted and the energy of the photons is converted to ...
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Explaining adabatic transportation of an electron in terms of the quantum Hamiltonian
In several text I read, it is assumed that when transporting and electron along a curve $C$ in magnetic field, (the quantum Hamiltonian of the electron is $H=(p-qA)^2/(2m) + qV$) the wavefunction ...
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de Broglie wavelength of electron
Why is the de Broglie wavelength of an electron $h/p$ since in Einstein's equation for energy of a particle, the rest mass of an electron is non-zero? What is the derivation of the wavelength in case ...
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EM waves and electron waves
If electrons are also waves then how can they produce EM waves when they "jiggle" due to temperature rise
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How do electrons move through conductors? [duplicate]
I am a bit confused about how electric charge or current moves through different conductors like steel, silicon, and even water. Is water classified as a conductor? And how exactly does the current ...
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Doesn't charge carrier density depend on the charge of the metal?
Imagine a sphere and wire charged to $10 \ \text{V}$ is connected to a neutral sphere. There are more charge carriers on the $10 \ \text{V}$ sphere and wire, so surely more electrons flow through the ...
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Can I apply the results of the Drude model separately for each charge carrier in semiconductors?
For example, since $v_d = \mu E$ in the classical Drude model, can I just assume the following?
(1) $v_d = \mu_{\text{hole}} \cdot E$ for hole
(2) $v_d = \mu_{\text{electron}} \cdot E$ for electron.
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What makes classical Rutherford model unstable?
Every reference to the classical Rutherford model of atom claims that it is unstable since the electron is radiating energy and so it should collapse into the nucleus.
But I had a confusion with the ...
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Wave-particle duality? [duplicate]
What does it mean for an electron to behave as a wave? I can visualize electrons or other subatomic things as particles. But what do we mean when say it's all a wave. What is waving actually? Waves ...
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When an electron jumps from higher to lower orbit, how does it not violate the law of conservation of mass?
I am just a higher secondary school student who was recently studying Bohr's model of the atom when this question popped into my mind. I know that when the electron jumps to lower orbits it releases ...
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What is the maximum amount of energy one electron can have? [closed]
Is there any limit on the amount of energy one free electron can have?? Certainly there should be a limit. I think High Energy Physics should be able to answer it. Please somebody help.
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Which electrons interfere in the double slit experiment? [closed]
In the double slit experiment, single electrons are fired at the double slit barrier. These electrons interfere with themselves, but do they also interfere with other electrons in the past and future ...
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Why doesn't the number density of electrons increase with increase in temprature?
It is said that for some increase in temperature of a conductor there exists only some decrease in the average relaxation time of electrons in that conductor due to increase of their thermal ...
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Why is the Van Allen belt located in that specific position?
I have read that the inner belt is located between 1,000 km and 12,000 km, followed by a slot region, and the second belt extends from 13,000 km to 60,000 km. Why are the particles trapped at these ...
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Why is there a huge difference in electron speed when an electron pulses vs. in a conducting wire?
I just read that "Physicists have created the world’s fastest microscope, and it’s so quick that it can spot electrons in motion (when electrons pulse, whatever that means).....This is is quite a ...
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Replenishment of electrons in an AC wiring system, after disconnecting battery charger?
I was wondering when you have a system which begins of course with the source of AC Electrical current, are on an isolated segment of that system, say connecting a segment of the power grid to a house,...
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How electrons are produced in Scanning Electron Microscopy (SEM)?
I am referring to thermionic emitter using tungsten filament, as a current is applied to the filament and transfer heat until sufficient energy overcomes the work function, then the electron are ...
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What is free electron? [closed]
If the standing wave model represents an election on the atom's orbital, what does the model represent the free election? Is the free electron experiencing any "excitement" phenomena?
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Electron spin in Pauling's General Chemistry book
I have a question regarding the interpretation in General Chemistry by Pauling (p. 77 - 78) about the spin of the electron/ it's angular momentum vector direction in a magnetic field:
It was ...
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Current operator for Bloch electrons [closed]
I'm trying to understand why in some lectures or review (e.g. in QHE lectures by Tong, or in the review Topological Field Theory of Time-Reversal Invariant Insulators by Qi), they say (without a proof)...
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Wave-particle duality: interactions of like / different quantum fields
With my pop-sci level of understanding, it seems to me that quantum fields exhibit particle-like properties only when interacting with a different quantum field - i.e. electromagnetic field interacts ...
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What is the proper ansatz for describing an electron-photon many-particle System?
I am somewhat used to simplified non-relativistic quantum mechanics (both canonically and grand canonically), describing a system by a Hamiltonian containing a kinetic part, an external potential as ...
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The size of elementary particles [duplicate]
There is no evidence that particles like electrons have inner structure.
The question is, when people say that electrons are point-like do they mean:
If we measure an electron to be localized to ...
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Can a Wigner crystal form spontaneously, or it will always need an external confining force field?
As far as I know, a Wigner crystal could be formed spontaneously from a free electron "cloud" with the right conditions (low temperature and electron density). Would it be stable and not ...
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Radiative or non-radiative emission
If a material absorbs photon, it's electron on outer valence band absorbs its energy and jumps to the higher energy level, when the band gap is similar to the photon's energy. If so, what determines ...
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Double slit experiment with two sources
A double-slit experiment with one source produces an interference pattern. Now what if we have two different sources of the same wavelength and a path length adjustment tool (maybe a liquid column ...
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Can there be clouds of free electrons in space?
Electrons are repelled from each other by the electromagnetic force, which is stronger than gravity. However, if there is a sufficiently high amount of free electrons in some region of space, could ...
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Is it true a cloud of free electrons emits no radiation?
We all know that atomic matter emits blackbody radiation according to its temperature even if no electrons are excited within that matter, however as far as I know no mechanism exists for blackbody ...
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Are protons and neutrons truly spherical and round like they are drawn? [duplicate]
I was watching a documentary "Visualizing the Proton: A Documentary" (link)
And this image of a proton popped up. So that got me my question.
Moreover, what about electrons and other ...
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How can electrons hop large distances if they are connected to the atom which is stationary in an lattice?
How electrons in valency and flow as they are connected to the atom and the atom is stationary but the electron travels way more distance than the size of atom that causes conduction?
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Is expansion necessary for negative heat capacity?
Gravitationally bound gas has negative heat capacity. It expands and its temperature decreases as heat is added.
What about electromagnetically bound systems such as solid materials? Is it possible to ...
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How Are Fractal Wood Burning Patterns produced by DC Electricity?
Here are 3 typical videos of fractal wood burning: video 1, video 2 and video 3.
As can be seen in all the videos, the different Lichtenberg figures develop simultaneously from both the positive and ...
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Why don't electrons measure each other in the YDSE?
Why don't electrons measure each other in the YDSE?
Assuming that the electrons are emitted as a spray and not one by one (which I think is reasonable), why don't two electrons measure each other ...
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Electron speed in the classical atom
In the classical (Bohr) model of the atom, does an electron in an outer orbit travel at a greater or slower speed than an electron in an inner orbit?
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Repulsion in electron amplitude
The question that continues to haunt me since I learned Wavefunctions and Schrodinger Eqns. is:
Why does, repulsion not occur due to orbital mixing since the dense electron cloud will still continue ...
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