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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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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44 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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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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28 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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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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49 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
49 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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20 views

Are electrons packets of energies made up of strings? [closed]

I always wondered that if electron was a packet of energy it would hold true for most of the experiments and we won't need to deal with wave particle duality anymore,but then matter came in.what if ...
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33 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
50 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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58 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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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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59 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
57 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
53 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
196 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 ...
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1answer
69 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 ...
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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
170 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
50 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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24 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
53 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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23 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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73 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
21 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
36 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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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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52 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?
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2answers
39 views

Fermi-Dirac distribution - holes and electrons

The density of probability of an energy state $E$ being occupied by an electron is $$f(E,T)=\frac{1}{1+e^{\frac{E-E_F}{kT}}}$$ and the density of probability of an energy state being occupied by a ...
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2answers
51 views

How can an electron's magnetic moment precess around the direction of an external magnetic field?

I am reading this article: The Nature of the Electron by Don Lincoln in The Physics Teacher, Volume 54 (2016), pg. 203, and I ran across the part where he talks about measuring the magnetic moment of ...
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1answer
26 views

Are the value of the magnetic field of a current carrying coil and the magnetic dipole moments of the involved electrons comparable?

The magentic dipole moment of electrons is a intrinsic property. To get the macroscopic effect of their common magnetic field this moments have to be aligned, like in permanent magnets or in current ...
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1answer
49 views

evidence for wavenature of particles from deBroglie wavelength [closed]

Doing a search on electron diffraction this, for example http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/davger2.html , the evidence does not look overwhelming for the significance of the deBroglie ...
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65 views

bare Phonon and Symmetry Breaking

In condensed matter physics, the phonon is considered as a quasiparticle which is a result of the quantization of lattice vibrations. In many textbooks on solid state physics, it can be done if we ...
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2answers
55 views

Why , under constant light intensity and constant frequency, do electrons emitted from a metal surface travel at different speeds?

I was playing around with this PheT simulation: https://phet.colorado.edu/en/simulation/photoelectric Under a certain threshold wavelength and an intensity at 20%, the electrons were being emitted ...
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1answer
89 views

Electrons motion

Some days ago, I was reading a very simple text about photoelectric phenomenon (at high school level) that this question came to mind. How do electrons move (for example during their translation from ...
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3answers
85 views

Why can't electrons absorb any energy (i.e. absorb some energy of the photons necessary and emit the residual)?

Recently I had a question in mind about the absorption of photons. Why is it that only specific energy levels can be absorbed by electrons? I mean, I get the idea that electrons in an atom have only ...
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2answers
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Atom Particles Relationships

I am an agriculture student, and we study tons of chemistry, and despite I took the exams I still have a good doubt on atoms. Through my studies I would say electrons are very tiny containers of ...
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1answer
32 views

How do quarks interact with the higgs field

I know that electrons' only interaction with the higgs field is due to ambidextrousness and the weak hypercharge which is provided by the higgs boson, but how do quarks (specifically up and down) ...
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3answers
113 views

Composition of energy of electron? [closed]

Mass energy of electron is 0.510 998 9461MeV/ c2 1) Does it include energy of electron due to electric field too? 2) If yes, how much? I am more interested in second part. Links:Here John Rennie ...
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24 views

How does a linearly polarized spin 1/2 wave look like?

Spin 1 waves are easy to illustrate and a linearly polarized spin 2 wave looks like this, but what is the counterpart for a spin 1/2 wave?
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1answer
56 views

What happens when fast moving electrons hit hydrogen molecules?

Just like the creation of X-rays. Where fast moving electrons are bombarded on some Heavy element. What happens if the we keep compressed Hydrogen instead of the heavy metals? Surely it will form ...
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3answers
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How come light waves don't get caught and absorbed by the electrons of oxygen atoms in the in air?

Shouldn't air be opaque since instead of coming into our eye, the lightwaves get caught in the electrons? If oxygen does absorb light waves, how come air is not hot and you can see through it? The way ...
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1answer
85 views

Why do electrons not fully fill up all the orbitals sequentially?

Why do electrons not fully fill up all the orbitals sequentially? By this I mean: why don't the electrons fully take up the previous orbit first and then move onto the next orbit? Take calcium for ...
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1answer
31 views

Why don't degenerate gases expand from heat?

Degenerate gases are excellent conductors of heat. However, the fermions that compose the gas will not expand outwards due to heat, except in incredibly high temperatures. Why is this? Does it have ...
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1answer
65 views

Concerning The Oil Drop Experiment: How does ionizing radiation create the electron(s) that the droplets of oil collect?

Concerning the Oil Drop Experiment: I read, “Ionizing radiation is used to create the electron that the droplets of oil collect. When the air in the apparatus is bombarded by this ionizing radiation ...
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1answer
15 views

Methods to ioniz air molecules

What are other alternatives ways to ionize air molecules, except the electric field charging and the use of the so-called corona discharge?
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1answer
15 views

Why does sodium emit yellow and boron green? regarding specifics of electron jumps.

So sodium emits yellow light when excited, and boron green but why? what about an electron jump causes some to emit higher energy frequencies then the others? For example, is higher energy (always?) ...
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1answer
54 views

What is the accuracy when firing an electron at a target?

Consider firing an electron at a target. Let the target be at a distance $d$ and the electron be travelling at a non-relativistic speed $v$. How can we estimate the maximum possible accuracy ...
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3answers
101 views

Relationship between electrons (leptons) and quarks

I assert the following is true: Either: electrons are made up of (two) quarks Or: Quarks are made up of some kind of smaller particles, which also make up electrons. I think this must be the case ...