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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Do electrons have intrinsic speed?

Absolute zero is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. At absolute zero ...
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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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Electron spiraling into nucleus [duplicate]

Any idea why it is said that, if electron is a particle it'll spiral into the nucleus and disintegrate in 10^-14 seconds? https://youtu.be/2wF_CVuWyEg?t=123 to https://youtu.be/2wF_CVuWyEg?t=142
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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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Left and right handed electromagnetic radiation from different subatomic particles?

The acceleration of electrons in an antenna rod produces a radio wave with its oscillating electrical and magnetic fields. For a vertically oriented rod the electric field points up- and downwards. ...
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How the infinite electric field of an electron goes through a slit? [closed]

An electron is an indivisible particle and its electric field has to be a constant too. Going through a slit how the electric field goes through the wall and how it will be regenerated behind the slit?...
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Why don't electrons and protons in a white dwarf combine before the electrons become ultrarelativistic?

I wanted to get a rough picture of how white dwarfs and the Chandrasekhar limit work. I wound up with an argument nearly identical to this one on Wikipedia up through the non-relativistic white dwarf. ...
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Are oscillations of electron chirality experimentally observable?

Is there any plausible experiment by which chirality oscillations in electrons could be observed experimentally, such as through some analogy to neutrino oscillation experiments?
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Why do photons excite electrons?

I know that when electrons encounter photons, they become excited and move to an orbit farther away from the nucleus of an atom as a result. What I want to know is exactly why the photons cause the ...
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Is gravity non-negligible compared to the electromagnetic force?

Consider two electrons approaching each other at rather fast speeds, maybe even coming close to colliding. Does gravity play any role in this event? If so, how much influence does it have? Do we need ...
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Why doesn't an electron's charge rip the electron apart? [duplicate]

Like charges repel. What keeps an electron's charge from repelling itself? This problem would come up if an electron was divisible and its parts had fractional charge. A related question is, ...
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If an atom is fully ionized by removing all electrons, is it still an atom?

This is a question about terminology. To me, it's clear that the nucleus of an atom is still an atom. But a comment by Willie Wong at Is nature symmetric between particles and antiparticles? raises ...
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Bekenstein bound for electron?

Using the Wikipedia version of the Bekenstein bound, and substituting the Wikipedia values for electron mass and radius, one obtains 0.0662 bits. Does this really mean that a system, any system, ...
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How do electrons actually move in a wire? [duplicate]

Do they jump from atom to atom or are they free-flowing? Where does resistance fit in? Do electrons physically HIT the atoms? If so, how do they hit atoms if the nucleus is small and far away from the ...
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Path taken by electron returning to ground state

Sometimes electrons are excited and return to their ground state in one step, while sometimes they take multiple jumps. What determines the path they take?
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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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Where do free electrons come from?

Here's what I what to know... Atoms have a nucleus that's positively charged and the negative electrons flow around it. Well when you pull the negative electrons off the atom where do the new ...
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Question on static electricity & electron transfer

Static electricity is caused by the transfer of electrons between substances right? For example, take a balloon and your hair. Both are stable and electrically neutral. So why would electrons jump ...
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Can an excited atom have multiple electrons in excited states?

For an excited atom, is it possible for the atom to be excited twice, having multiple electrons in higher energy levels than for the atom in its ground state? If it is indeed possible, what is the ...
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Electron degeneracy and helium flashes in stars

I have a question regarding the above mentioned. When a star have a mass of about 3-8 it does not go through the so-called helium flash phase, but instead just run along as nothing had happened, turn ...
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Why does my shirt make a crackling noise when it is static?

I thought that when clothing becomes "static" (used as a colloquial adjective for that state when clothing fresh out of the drier sticks to everything) it's because of a build up of electrons. That's ...
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Can I move the atom nucleus only?

I was wondering if it is possible to move the atom nucleus and leave behind the electrons? I can imagine that the electrons will follow the nucleus. But what if the speed of the nucleus is almost the ...
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Momentum of an electron acting as a wave [closed]

Was working on a problem with electrons acting as waves in diffraction. Part of the question asked me to calculate the momentum of the electron. Since I was dealing with waves I used the following ...
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Will Positron Cause flow of electricity?

Recently someone told me about antimatter. Antimatter is something that is completely opposite to matter. What I would like to know is let's say this universe was made of Anti-Matter. So since the ...
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Why does exchange lower energy with increasing electron density in Hartree-Fock

The Hartree-Fock equations include a term for the exchange interaction, which is usually explained as a repulsive force due to the Pauli exclusion principle. (It says so right in the description for ...
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How does the orbiting of electrons around nuclei START? [closed]

When electrons orbit a nucleus, their orbiting continues due to conservation of angular momentum, so I've read. But what causes an electron to orbit a nucleus in the first place? To be more precise, ...
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Conductance of semiconductors at very high temperatures

The restivity of typical conductors tends to increase as temperature increases. From what I understand, this is due to electron scattering. Semiconductors tend to have their restivity decrease as ...
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Are free electrons truly free?

As this diagram shows, energy levels get closer together as they get higher. Is a free electron then truly free? Or is it in such a high (bound) state of energy that the transitions become nearly (but ...
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Dependence of the energy of an electron on distance from the nucleus

I was going through an article given to me by my teacher which gave info about the influence of the positive nucleus on the electrons in the 's orbital', 'p orbital' and 'd orbital' respectively. Here ...
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What happens to the electron in a beta minus decay?

We know that in a beta minus decay the neutron decays into a proton, electron and electron antineutrino. So let's assume we have a vacuum chamber full of free neutrons which after sometime decay in to ...
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Do electrons have a radius when they behave like a particle?

I know sometimes electrons behave like waves, but it sometimes can be seen as a particle. while it's a particle, does it have a radius? or, a volume? If it doesn't even have a volume, how can we still ...
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Mass of the electron

In the classical limit, three quarters of the mass-energy of the electron come from the energy of the electromagnetic field of its charge (see Electromagnetic Mass). Intuitively one would expect that ...
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Why is the direction of cathode rays independent of the position of anode?

The following statement is from the book Concepts of Physics Volume 2, by Dr. H.C. Verma, chapter 41 - "Electric Current through Gases", topic "Cathode Rays", page 343: Cathode rays are emitted ...
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Static electricity - what is it?

I'm just having some difficulty with completely understanding the concept of static electricity. What actually happens? Is it because the electrons cant move? And if so, why can't they move?
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Free (unbound, so not bound to a nucleus) accelerated electron cannot emit/absorb a real photon?

I have read these questions: Can a free electron absorb a virtual photon even though it cannot absorb an ordinary photon? Where Michael Seifert says: It is entirely possible for a real electron ...
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How is the energy of an electron-shell related to the speed of electrons in that shell?

I am trying to gain an intuitive picture of what is referred to by "electron-shell energy". I have read that outer electron shells have higher energy than inner electron shells, and this seemed to ...
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Why does the electric dipole moment of the electron tell us about its sphericity? [duplicate]

There are a bunch of experiments that claim to show that the electron is highly spherical by measuring the electron electric dipole moment. See e.g.: http://physicsworld.com/cws/article/news/2013/nov/...
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Energy band theory: conduction of electrons and holes

My textbook, Introductory Semiconductor Device Physics, by Parker, says the following in a section on energy band theory: We are aware that conduction in most metals is by electrons but conduction ...
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Energy of electrons in wire

The Drude Model helped me quite a lot to visualize how current could flow in a circuit. However, there is still a point that I cannot grasp in the explanation given by some people when they talk about ...
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What happens to an electron in a molecule once it has absorbed a photon and transitioned?

Say we have a molecule capable of absorbing a photon somewhere in the UV/Vis region of the electromagnetic spectrum. Once this electron has transitioned to a higher energy state, does it just stay ...
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What is an electron? Is it an orbital?

Is an orbital a wave or is an electron a wave? Does an electron exists in an orbital or is an orbital a wave cloud of electrons? Is there really particle inside an orbital or is an orbital a particle?
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Electron Electric Field Mass?

I am confused of whether or not the expected electromagnetic field generated by the point-like electric charge of the electron distributed smoothly across space as a probability distribution creates ...
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Element 137 - Theoretical limit [duplicate]

I've seen a few sources that mention the speed of an electron in a hydrogen atom is 1/137 the speed of light. This article also mentions what looks like a correlation between atomic number and the ...
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Is an object's color/shine/texture dependent on its electrons only? If electrons are same then why are there so many different colors?

when we look at an object be it a metal or a non-metal are we looking at its electrons only, so then if all electrons are same then why do different chemicals or elements or objects have different ...
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Landau levels in 2D

I seem to be having a very basic misunderstanding of Landau levels in 2D. Consider the derivation give on page 7 here, where we consider electrons free to move in 2 dimensions, with a magnetic field ...
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Can why electrons exist in shells be explained by the Pauli exclusion principle?

Do you know the Pauli exclusion principle?-'No two particles could be in the same quantum state at once'. Well can you use that principle to explain why electrons stay in shells and electrons in ...
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How fast does an electron jump between orbitals?

I'm wondering what speed electrons jump from level to level. I've been told only that they emit light when doing so and need energy to be inputed in order to occupy orbitals closer to the nucleus. I ...
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Positive test charge

Protons have positive charge on them. Protons aren't mobile. So how can a positive test charge move from the negative terminal of a cell to the positive terminal and gain electric potential energy? ...
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Dispersion Relation (e vs. k) clarification (crystal momentum or electron momentum)

If we get the dispersion relation from the Fourier transform of the lattice vectors then how do we get electrons information? Specifically, for the $k=0$ point of the graph, does this mean the ...
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Electrons on Stern–Gerlach experiment

My questions about spin and negative charge of electrons. Stern-Gerlach experiment is very famous in order to find spin of electron. this video created by paris-sud university really well-explained on ...

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