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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Charge of electron in AC/DC circuit

If electrons in a DC circuit going through a metal wire carry only negative charge from negative to positive, then in a AC circuit through a wire does a electron carry both a negative charge and ...
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2answers
44 views

Why is the energy expressed in an electron orbital change of state electromagnetic (photon)? [on hold]

As I understand it, Schrodinger's wave equation predicts the allowable energy states an electron can have under the electromagnetic forces of a given nucleus (and I assume other 'orbital' electrons). ...
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8 views

Shape of electron energy deposition profile

The energy deposition profile of an electron beam impacting a material has this characteristic shape (1 MeV beam in Cu):* What physics mechanism would refer to the peak energy deposition at ~ .2mm ...
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25 views

Cathode ray experiment

How are electrons in a discharge tube emitted from cathode under low pressure and high voltage ? For example in a thermionic emission they are released due to the excess energy they get as heat which ...
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2answers
84 views

As electron is accelerated nearly to the speed of light what would occur? [on hold]

What would occur if an electron at rest was accelerated nearly to the speed of light? Would the photons emitted by the electron approach a gamma wave photon as it approached the speed of light, or ...
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41 views

How Light interacts with Atoms? [on hold]

I think I have confused myself about how light interacts with matter, would somebody be able to clear these questions up for me? How does an atom reflect light? Can an electron just essentially '...
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1answer
44 views

Speed of electricity in a tangled wire

Most sources claim that the speed of electricity in a wire (or signal/information speed) is the EM wave propagation speed of the metal. What about tangled wires? Am I correct in assuming that for the ...
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0answers
27 views

Can an electric circuit be modeled from tracking individual charge carriers?

Given a simple electric circuit , If we were to start from tracking all the forces acting on each individual free electron in the circuit, would it be possible to eventually find all the currents and ...
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1answer
52 views

What is the capacity of an electron to absorb energy? [closed]

When an electron get excited we find that electron absorbs energy and jumps to the required shell. This means that electron can absorb an infinite amount of energy and can get excited to infinity ...
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26 views

Need an answer for a simple question, how does an electron propel itself? [closed]

The thing is that even with all these math tricks going on an crazy theories poping up solving mysteries of the universe, I don't seem to find the answer why electrons move, the question might be a ...
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1answer
184 views

Experiment that demonstrates the wave-particle duality of electrons

EDIT : You're about to read the first iteration of my question which is flawed. Please go to the end to see an illustration of what I meant to say. The phenomenon I was talking about is called ...
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1answer
45 views

Why does distance between electron shell decrease in going away from the nucleus? [closed]

Is there any particular reason why the distance between electron shells decrease as we go further away from the nucleus?
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33 views

Electron Beam does not appear to be continous (CRT Experiment)

https://www.youtube.com/watch?v=2xKZRpAsWL8 Why do you see patches of purple in the tube? Shouldn't there be continous lines of colour? As far as I know, you see the rays because some of the ...
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3answers
62 views

Electron deflected by moving magnet

My original question was far too long, so I am editing it down to this much smaller version: The Lorentz force for an electron traveling through a uniform magnetic field with no electric field is $F=...
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1answer
64 views

Could Absolute Zero Stop an Electron Beam? [closed]

Context: Okay, I have a comic book scenario and I want to know what would happen. Fighter A can forcibly control electrons in the state of an electron where it is both particle and wave, and when ...
3
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1answer
42 views

Electron traveling through gravitational and magnetic field

When an electron travels through a magnetic field it experiences the Lorentz force. The force acting on the electron causes an acceleration and therefore Cyclotron radiation is emitted. After reading ...
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1answer
23 views

Cathode Rays Experiment by Sir J.J.Thomson

From where do the electrons making cathode rays come? How is the gas in a discharge tube ionised? Do cosmic radiations affect it?
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0answers
15 views

electrical pulse or data transmission

Electron flow in an electric circuit I understand to be slow. Movement of an electron in an orbital is pretty fast, but much less than c. The apparent movement of a pulse down a conductor however, ...
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1answer
38 views

Einstein coefficients for emission/absorption and energy density

When dealing with a system of two energy levels $E_1$ and $E_2$ in laser theory, the following rate equations are written: $$\frac{d N_1}{dt} = A_{21}N_2 - B_{12} \rho ( \nu ) N_1 + B_{21} \rho ( \nu ...
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1answer
129 views

Classical Mechanics as an approximation of Quantum mechanics [closed]

I want to show an equality: We know from Ehrenfest's theorem that $$ \frac{d \langle x \rangle(t)}{dt}= \left\langle \frac{\partial H}{\partial p} \right\rangle $$ I'd like to derive the ...
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3answers
719 views

Is there strong interaction between electrons?

I am not familiar with quantum mechanics at all. But I remember when I was at high school, we learned that strong interaction keeps protons next to each other while they repel each other because of ...
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0answers
23 views

How does an electron interact with an electron neutrino?

An electron and neutrino come close and they exchange a W boson and then they change places.. but why? A neutrino has no electric charge, so how do they know to interact?
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1answer
38 views

Refractive index of plasma dependance on temperature

How does the refractive index of plasma changes with temperature? Temperature is not high enough for new ionization. Would it be like in gas p/T dependence ? http://farside.ph.utexas.edu/teaching/em/...
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2answers
85 views

Is the Pauli exclusion principle also involved in free electrons?

Imagine I want to make a laser of electrons like a laser of light. Is that possible, or does the Pauli exclusion principle prohibit that?
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1answer
35 views

Shared electron behaviour in a covalent bond

Some basic questions: 1) I can't figure out how two atoms form a covalent bond. We say two atoms make a covalent bond when they share an electron. On the other hand, we know that electrons circulate ...
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1answer
50 views

Number of electrons in conduction band

As mentioned in a previous question, the number of electrons in conduction band in a semiconductor can be computed as follows: $$N = \int_{E_c}^{+\infty} g_c(E)f(E)dE$$ where $g_c(E)$ is the density ...
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7answers
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Prove that an electron in a hydrogen atom doesn't emit radiation [duplicate]

According to electrodynamics, accelerating charged particles emit electromagnetic radiation. I'm asking myself if the electron in an hydrogen atom emits such radiation. In How can one describe ...
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0answers
54 views

Rotating fermion and spin structure on manifold

We know that doing a 2$\pi$ rotation would give a minus sign to wavefunctions of electrons. Since electrons are spin $1/2$ objects. How is this related to the spin structure on the manifold in which ...
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1answer
55 views

Is there a way to strip all the electrons from single atom with atomic number greater than 2

Please explain by what means electrons extraction can be done. How person can focus activity on single atom (from precision point of view) to do so? How at each step person can know how much electrons ...
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1answer
39 views

Earthing, neutral and Earth's conductivity

Ok so this is gonna be a lot of mini-questions. What exactly is the neutral wire? How does earth conduct electricity for a live AC mains even though its just dirt and stones (it should be an ...
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1answer
54 views

Solid state physics: When do I use classical laws?

Let's say I am given the dispersion relation for nearly-free electrons: $$ E(k) = \frac{\hbar^2}{2m}(k^2+c\,k^4)$$ Where $c$ is a small constant of appropiate dimension. How do I calculate the ...
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0answers
61 views

Electron spinning speed and “matter” it is made from

I wonder how electron may have spin if its model has no space occupied solely by the electron. Is it possible to estimate this rotation speed knowing its mass, charge and magnetic field emerged? If ...
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0answers
27 views

possibility of interference of electrons during its transition from higher to lower state

They say an electron possesses dual nature (what we call wave-particle duality in order to relate with our everyday world). If it is an electron (definite particle) it too shows wave-like phenomenon ...
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1answer
64 views

Density of states from $k$ to $E$

Speaking about Quantum mechanics, considering the "particle in a box" condition as an approximation of the electrons condition in a semiconductor, let the material be represented by a volume $V$ with ...
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1answer
59 views

Solving a step in the derivation of the anomalous magnetic moment of the electron

In the book An Introduction to Quantum Field Theory by Peskin and Schroeder there is a derivation of the anomalous magnetic moment of the electron. The Feynman diagram to be solved is this one: and ...
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1answer
64 views

Fermi Dirac distribution and degenerate energy states

In Quantum Mechanics and in semiconductor materials, the number of electrons $N$ in conduction band is usually computed as follows: $$N = \int_{E_c}^{+\infty} g_c(E)f(E)dE$$ where $g_c(E)$ is the ...
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3answers
203 views

How do we know that an electron “spins”?

As far as I know, you can't necessarily isolate an electron to observe it, you can only observe its effects on other particles due to fields. Moreover, we can't know an electron's exact location or ...
5
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1answer
73 views

What happens to the electric field lines when an electron and positron collide? [duplicate]

A month back I began my course in classical electrodynamics. I know about the field lines of moving charges. But I have this question that if an electron and a positron are situated some distance ...
2
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0answers
98 views

What is the influence of QED vacuum in electron-double-slit experiments?

In a recent question on superpositions of different quarks it was explained, that the superpositions of different electric charged particles cannot exist, in contrast to strangeness quantum number. It ...
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2answers
173 views

According to relativity theory, what is the force that two electrons moving radially apart exert on each other?

According to relativity theory, what is the most general expression for the force that two electrons moving radially apart exert on each other? I am looking for a function $$F(r(t)),$$ where $F$ is ...
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1answer
51 views

Direction of momentum given by the de Broglie relation

The momentum of an electron can be computed by the well-known classical mechanics equation: $p=mv$ where $m$ is the mass of an electron, and $v$ is its velocity. In this case, since $v$ is a vector,...
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1answer
28 views

Why is collision of electrons different from alpha particles in terms of probability amplitude?

In The Feynman lectures on physics volume 3, chapter 3, page 3-11, there is the following paragraph: An even more perplexing thing happens when we do the same kind of experiment by scattering ...
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1answer
35 views

Can an electron make quadrupole gravitational waves?

A gravitational wave is a quadrupole wave. Now when an electron is accelerated it usually emits a photon. But can an electron also emits an gravitational wave? If so how does it 'make' an quadrupole ...
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1answer
55 views

Why can't we use a capacitor to detect electrons in the electron double slit experiment?

So, basically I have been learning Quantum Mechanics online and I leant about the double slit experiment with electrons, wherein if you try to detect an electron with a light source having wavelength ...
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1answer
35 views

Kaufmann's experiment 1902

Kaufmann's experiments (1902): http://en.wikipedia.org/wiki/Kaufmann%E2%80%93Bucherer%E2%80%93Neumann_experiments#Historical_context About charge to electromagnetic-mass ratio. Fig 2 has a plot of ...
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79 views

How do we know that electrons are affected by gravity?

There are some theories of gravity which explain it as emerging from other fundamental forces. To better understand the evidence for and against these theories, I would like to have a better ...
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3answers
25 views

Difference in directions of charge and current.?

I just dont understand that why does charge flow in a different direction as that if current when current is the rate of flow of charge.
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2answers
37 views

Why does electromagnetic induction creates both voltage and current but static electricity only creates voltage and no current?

Why is it that electrons do not move the same way in triboelectric as in magnetic induction when both creates voltage? Triboelectricity can even create tens of thousands of volts like Van De Graf ...
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20 views

Ionospheric electron density measurements

I've been working on measuring total electron column density (TEC) with multi frequency GPS data. In theory, signal delay caused by TEC differences should affect the code and carrier nearly evenly in ...
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0answers
53 views

Relativistic mass of electron in a potential [closed]

An electron is accelerated through a 6 MV potential difference. what is the mass of the electron at the end of the path?