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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What is the ontological status of gauge fields/virtual particles/electron radiation in Dirac sea model of Bohmian QFT?

I have been reading about this model - it is a model without actual particle creation or annihilation, particles move deterministically according to Bohm's law, the Dirac sea is used to explain away ...
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Explanation of momentum/energy arising due to uncertainty principle

While discussing the stability of hydrogen atom, specifically why the electron falling into the proton won't be the minimum energy state, the reason given is based on uncertainty principle. That the ...
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What's magnitude of the spin of an electron in a superposition state two spin states?

An electron is said to have the spin magnitude of -1/2, and this is often called one of the 'intrinsic' properties of an electron. Does an electron also have a spin magnitude -1/2 when it is in a ...
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Why heating a white dwarf shrinks its degenerate core?

I tended to think that under electron degeneracy, electrons are spread over more energy states instead of being spread over so much space, so the exclusion principle lets more electrons to be ...
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With how much energy can a charged black hole launch a electron away with?

Lets say with have a black hole with a strong negative charge, then a say a neutron falls towards it. Just before the neutron reaches the black hole's event horizon it undergoes beta decay, this ...
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Why do electrons stop in PN Junction?

I understand that in a PN junction the electrons move from the n region to holes in the p region. I don't understand why the electrons don't keep moving from hole to hole until they get to the end? If ...
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Why is current = 0 in open circuit?

This is an open circuit. Now , a chemical reaction happens in the cell which makes the current to flow in the wire. Then , the current has no other place to go , so it just gets grounded. It is ...
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What are the steps that give rise to this following resistance equation for a diffusive transport of electrons?

$ R = R_b (1 + \frac{\lambda}{L})$ Source - page 6 of this book: https://nanohub.org/courses/FON1/01a/asset/15698
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Electric field needed to remove an electron from a Helium atom

Let us consider that we have a Helium atom. We have provided an electric field $E$, which is sufficient to pull out an electron from this atom. We can calculate this electric field as follows : $$eE=\...
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How can a point particle have orientation? [duplicate]

I always thought that a point particle would have spherical symmetry. This is the case for the intrinsic electric field from an electron. However, the intrinsic magnetic field of an electron has ...
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Can electric charges really be positive and negative?

This question is my extension to this one. Please excuse if it sounds too naive, as I am not a physicist by trade. From the above linked question and answers to it I understand no physical phenomena ...
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In what physics scenarios is it appropriate to consider an electron a ball, vs. a cloud, vs. a probability distribution?

These articles says the electron is a near perfect sphere: https://futurism.com/electron-edm-experiment So, what is our intuitive answer to the question? In all artists’ impressions of the atom, we ...
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Clarification of semiconductor energy levels and bands explanation

I am currently studying Diode Lasers and Photonic Integrated Circuits, Second Edition, by Larry A. Coldren, Scott W. Corzine, Milan L. Masanovic. Chapter 1.2 ENERGY LEVELS AND BANDS IN SOLIDS says the ...
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Why Can Electrons be Modelled as Classical Spins?

Although electrons are spin $1/2$ particles described by the Pauli matrices, the Ising model treats electrons as classical spins. As a result, the Ising model does not describe anything physical, but ...
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How can the electron in a hydrogen atom have energy without angular momentum ($n>0$, $\ell=0$)? [duplicate]

Been struggling with this concept. Or is this just one of those things in quantum mechanics which attempting to understand is futile? Guess we can see it as the electron just linearly oscillating back ...
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What is the difference between the electron spin frequency and the electron Larmor frequency?

I am confused, WP says: "The spin g-factor is related to spin frequency $v_{s}$ for a free electron in a magnetic field of a cyclotron with frequency $v_{c}$:" $${\displaystyle \nu _{s}={\...
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Penning trap with positrons: observing annihilations?

Has a single positron been deliberately put into contact with an electron to observe the results? If so, does the annihilation occur only when the two particles "touch" or is the definition ...
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Electron separate from an atom -- still has same characteristics about location?

I have heard that a single electron has been trapped for a long time in I guess some kind of magnetic trap. I also understand that an electron in orbit around a proton in hydrogen atom is not really ...
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Grotrian diagram for Helium

Hi, is this Grotrian diagram for helium wrong? I can't understand how a $1s2d$ state is possible since my understanding was that the $d$ states only start at $n=3$?
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Will the electron in a circuit without a load gain ever more potential energy every time it passes through a battery?

Say we have a circuit without any load, just a wire and a 1.5 V battery, so there is no full potential drop as it gets to opposite terminal. Will there be 1.5 V of potential added every time it passes ...
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Having more electrons than the Fermi energy allows

What happens when we have more electrons in a solid metal than the Fermi energy and Pauli exclusion allows? Let's say we reduce the temperature to a level where all the energy states are filled with ...
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How to derive fluid equations for electrons from the linearised kinetic equations?

Starting from the linearised kinetic equation for electrons and ignoring perturbations of the ion distribution function completely, how can I work out the fluid equations for electrons (i.e., the ...
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Photoelectric effect conceptual doubt [duplicate]

My teacher told me that for emission of one electron from metal surface only one photon is responsible and electrons have different kinetic energy after emission as some of the energy is not absorbed ...
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Does an entangled electron retain its entangled state if introduced into a metal?

If an experiment is performed where a pair of entangled electrons is generated, and then one of the pair is introduced into a metallic body, for the sake of argument say a one centimeter cube of ...
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P-N junction and the physics of semiconductor-diodes

I'm trying to build a functioning mental model of the physics of a P-N junction and am looking to see if my reasoning is sound. A diode of phosphorous doped N-side and boron doped P-side. Phosporous ...
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Nearly Free Electron Approximation for 3D Lattice

I have been learning the Nearly-Free Electron approximation method and its application in one dimensional lattices. Since nearly all real-world lattices are three-dimensional, I am trying to apply ...
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In Drude model of conduction, are electrons moving across the conductive object?

As I understood, Drude model explains an electrical current as a chain of momentum transfer between electrons; In this sense, does a single electron leave its atom and move forming the electrical ...
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How many electrons should we remove? [closed]

To get a charge $Q=1 \text{C}$, how many electrons should we remove from a metallic sphere? I'm a aware that $Q=n.e$, but is this question true, because I believe we need an initial charge?
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Is hydrogen atom with a single unpaired electron diamagnetic?

I know that paramagnetism is caused because of the net magnetic dipole moment of an atom with unpaired electrons. On the other hand, all substances exhibit diamagnetism, but the effect is weak and ...
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Does the size of the mark a photon/electron leaves on a light sensitive sheet change with distance?

This video shows an electron detection event build up. https://www.youtube.com/watch?v=hv12oB_uyFs When firing photons or electrons at a light sensitive sheet (or whatever types of detectors are used),...
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What is the Hamiltonian of an electron moving through a conductor?

I am specifically asking for the formula for an electron moving through a wire. I would also like to know where it comes from/how it is derived. I was not able to find any answers for the potential ...
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Why do accelerating electrons not emit electromagnetic radiation?

I've read at many places that accelerating charged particles emit electromagnetic radiation, but on this article on Bohr's hydrogen atom, at the end part, it's written under Limitations of the Bohr ...
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Radio receivers and the loss of electrons

I'm reading Kenn Amdahls book "There are no electrons" to familiarise my self with the magical world of electricity. Despite Mr. Ahmdahls insistence on the non-existence of electrons, I find ...
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Why does supplying energy makes an electron go away from the nucleus?

My question is: the energy of electron is considered to be negative, so when the energy is supplied though photons the energy of an electron increases (tends toward positive direction) and they get ...
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Why an electron and a positron should have the same lifespan?

According to Particle Data Group: source: data Particles and their antiparticles (i.e. antimatter) have the same lifespan. The electron/positron for example have a minimum of 6.6E28 yr. This was ...
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Is there some relationship between circuit voltage and the speed of circulating electrons?

It is well-known that under an external electric field the work that a charge has to do to go from a point A to another point B is $w=-V_{AB}*q$, this is equal to $\int_A^B{-\nabla V·dl}$ which would ...
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Random Walk of Thermal Electrons

The drift velocity of electrons in a typical electronic circuit might be measured in mm per second. In contrast, the thermal velocity of electrons is in the vicinity of km per second. Because of the ...
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Would somebody feel a magnetic field if they are travelling at the same velocity as a charge?

I am little bit curious about how magnetic fields are being generated when a charge moves. I want to check if somebody travelling along with a charged particle, would that person experience a magnetic ...
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How does an electron actually find the stationary states (eigenstates) through time evolving using Schrodinger wavefunction?

I have a question regarding how the the stationary states (eigenstates) are arrived at in Schrodinger's wavefunction, please. In the graph below, taken from https://www.youtube.com/watch?v=2V0Xmc0ow80&...
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Explanation for exact amounts ratio between up,down quarks and electrons in a universe

As I've understood in the quark era $\approx (10^{-12} - 10^{-6}) \,\text{s}$ unified interaction has decoupled into Leptons and Quarks. Given that now Hydrogen+Helium atoms accounts for $97.9\%$ of ...
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Why are there (roughly, at least) equal numbers of electrons and protons in the universe, despite their hugely differing masses? [closed]

Other people have asked very similar questions, but I cannot find an explanation or question referring to their vastly differing masses (approx. 1836 to 1).... Also, if there are almost 2000 times as ...
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An electron's phase has to be shifted, forwards or backwards, by two full cycles to be indistinguishable from the original, correct?

Does anyone else watch PBS Space-Time with Matthew O'Dowd? His most recent episode, 'Why Magnetic Monopoles SHOULD Exist', says, at 7:25 to 7:45, that the shift in an electron's quantum phase is ...
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Should electrons from the silk handkerchief align their spins when we put close a permanent magnet?

Should electrons from the silk handkerchief align their spins when we put close a permanent magnet? So to produce an extra magnetic field that will add up to the field of the magnet?
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Does quantum mechanics violate the law of conservation of energy? [closed]

I recently learned that an electron can exist in two places at the same time simultaneously, which was pretty intriguing to understand. But to me there is seemingly a flaw in this fact. The charge of ...
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Can an insulator become a conductor at superconductive temperatures?

Can an insulator become a conductor at superconductive temperatures? As a part of electric resistivity is physical opposition to the stream of particles would an insulator having its nuclei inert in ...
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How do electromagnetic lenses magnify the image?

In optical microscope both objective and eyepiece are used to magnify the sample image. Magnification is determined by laws of geometrical optics (intersection of optical beams from the same point of ...
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Collision of an electron with an atom

What exactly happens when we say an electron collides with an atom? When we say atom, does the incoming electron collide with the nucleus of the atom (electromagnetic repulsion from the nucleus ,...
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Number of electrons in an atom referenced by Rutherford

I have been reading the original paper of Rutherford and came across his reference of a paper from J.A. Crowther. Crowther concluded that the number of corpuscles in an atom is equal to about three ...
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How to calculate electron flux from recorded dose in oncology calibration tests?

For the purpose of testing a diode response to electron and gamma irradiation, we have used a linear electron accelerator at an oncology facility. The 6 MeV beam with dimensions 40 by 40 cm was ...
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What is the essential difference between constant speed and acceleration?

I do know what the difference is but what I am trying to understand is how an object knows its speed is changing and/or how space knows an object is accelerating. The particular thing I am interested ...

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