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 difference between AC light and DC light or is there such a thing?

As AC is for alternating current and DC is for direct current, What is lights property (AC or DC) that travels? Example light from the sun. Is there an analogy on this?
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Why doesn’t the focussing anode diverge the electron beam again?

Consider this diagram of a focusing anode in a CRT: Question: Why does the electron beam not diverge again when it enters the focussing anode (or accelerating anode) while leaving the pre-...
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Why is lightning going from the Earth to the clouds while the electrons are going from the clouds to the Earth?

The lightning is often a discharge in advance. The (negative) charge slide occasionally a little further on in the conductive channel, wherein said channel is highlighted each time something. The ...
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Why are 2 gamma photons created? [duplicate]

When a positron and an electron come together they annihilate and produce 2 gamma photons $$e^+ +e^- \rightarrow 2\gamma$$ I can understand that they must be produced in pairs to conserve momentum. ...
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Is the magnetic dipole of the electron an intrinsic property?

The profound answer to the question How permanent magnets work? starts with Sub-atomic particles such as electrons, protons, and neutrons (and many others) have a fundamental quantity called a spin ...
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Are Cooper pairs (of electrons) entangled?

I have read this question: Does a normal torch emit entangled photons? where Quantum Journalist says: Although all the particles of a BEC are in a single quantum state, they are not ...
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In a circuit, do surface charges get influenced by external electric fields? [duplicate]

Hello ,This image represents surface charges in a circuit caused by the battery's electric field, if you were to place an other electric field source of the same magnitude (but not connecting it to ...
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Calculating force on electron

How do we calculate force on electron, knowing that it behaves both as particle and wave.
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How does a particle's energy determine interaction behavior?

I have been trying to get my head around Electron-Beam Lithography and have a small issue with what has been said in the linked YT video. At 11:35 Chris Mack says that The more energy the ...
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How did J. J. Thomson establish particle nature of electron? [migrated]

I've read about how the electron was discovered on Wikipedia and they have said that Thomson and his students performed experiments which suggested that cathode rays were negatively charged "particles"...
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How does a heated object lose thermal energy in a perfect vacuum?

Suppose I heat up an arbitrary object to an arbitrary temp and then place it in a near perfect vacuum (let’s assume inter-galactic space). If there is essentially nothing for the object to transfer ...
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Electrons direction in cathode ray tube

This image below show the movement of an electron in a magnetic field, it's taken from the video [Histoire des sciences] La découverte de l'électron explaining the experience of J.J. Thompson when he ...
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What will happen if I bombard electron beam on metalloid?

I know when we bombard electron beam on metals it gives out X rays, but my question is that what will happen if I bombard electron beam on metalloids?? please give answer
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How is hydrogen able to emit a light spectrum with only one electron?

When light is shined through hydrogen gas, three colors of light appear. The issue I have with this is that hydrogen has one electron, meaning somehow the electron has to be emitting all three of ...
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Why don't electrons crash into the nuclei they “orbit”?

I'm having trouble understanding the simple "planetary" model of the atom that I'm being taught in my basic chemistry course. In particular, I can't see how a negatively charged electron can stay ...
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When an electron changes its spin, or any other intrinsic property, is it still the same electron?

I am not asking why an intrinsic property, like spin can have more then a single value. I understand particles (electrons) can come to existence with either up or down spin. I am asking why it can ...
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Electric current and drift velocity

I have seen in several textbooks that say that when we connect a conductor with a battery then electrons start moving (drifting) in the battery in random up and down motion in the opposite direction ...
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What keeps electrons in an atom from flying away or falling into the nucleus?

In atoms, what force or charge, etc. keeps electrons from flying away or into their nucleus? is there a kind of weak-force at work on the atomic scale? Note I am aware the electron positions are ...
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Single electron in conductive cavity

It is a basic result in electrostatics that a charge $q$ in an arbitrary cavity of an ideal conductor will generate a total charge $-q$ on the surface of the cavity in such a way that the electric ...
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What happens to mass during beta decay?

Sorry for being ignorant, but I'm in high school and our chemistry teacher barely went over beta decay. I decided to do some research and learned that in β+ decay, positrons are emitted from protons ...
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Calculating velocity of electrons in a vacuum tube (read description)

If I use a high voltage DC current in a vacuum tube to bring a lower power AC current into a vacuum tube, how do I calculate the average velocity of the AC electrons?
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Is a purely Electron or Proton bomb possible?

Since electrons repel other electrons and protons repel other protons, if you had enough of either of these in an enclosed space, and suddenly removed the enclosing barrier, would the repelling force ...
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In the ground state properties of electron gas, is $V$ the volume of all the metal or the volume of a cell of the lattice?

In the ground state properties of electron gas (Sommerfeld theory), is $V$ the volume of all the metal or the volume of a cell of the lattice? I thought the latter because the Born—von Karman boundary ...
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What happens if you connect a wire to the anode of a battery, but not the cathode?

My understanding is that the anode of a battery is positive while the cathode is negative. If you connect a wire between the cathode and the anode, then the electrons in the cathode want to flow to ...
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Electron falling into proton approaches infinite kinetic energy why?

Foreword I believe this question to be different from the usual "Why don't electrons fall into the nucleus" because this A: asks about the details of explanations for why electrons don't fall into ...
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Nature of metallic bonding in solid state

What is the reason behind attraction of metal kernels & free electrons in electron sea model?
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Electromagnetic field of a point charge seen from a rotating reference frame

Let us consider a point charge sitting in the origin of our coordinate system. If we change to a rotating system, will the field of the point charge still look the same? Intuitively I would say yes, ...
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If air is an insulator, how does an ungrounded electric generator move electrons?

Firstly, this is NOT a duplicate question. There have been similar questions asked, but no one has adequately explained this particular aspect of electric generators. Yes, they act as an electron "...
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Are individual atoms inside a molecule (covalent) still really EM neutral?

I am not asking about ionic bonds. I am in this case asking about covalent bonds. I have read this question: Why do atoms repel when closer but attract when farther apart? Where Swike says: ...
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Constant term in the periodic Poisson equation [closed]

When we solve the Poisson equation with periodic boundary conditions we have to ensure that the integral of the right hand side is zero. That is, we neglect the constant term of the Fourier expansion ...
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What would happen if I bring an electron near a conductor

What would happen if I bring an electron near a conductor ?? Charges should be induced, but since a charge cannot be smaller than that of an electron, what could possibly happen ?? Eg : Say I bring ...
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Orbital wavefunction for a system of two electrons

I am new to this forum! I write here hoping someone can help me. I have found a statement in my quantum mechanics book that I really don't understand. We have a system of two electrons. If both are ...
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Electric field of electron in alternating potential

I am considering the case of an electron placed in an alternating sinusoidal potential, of frequency 13.56 MHz (frequency typically used for RF plasma generation). Suppose I have a simple 1D set up, ...
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Benefits and Drawbacks of Swapping Associations of Positivity and Negativity of the Proton and Electron

For historical reasons, I understand that a proton's charge was assigned the label of "positive", the electron's charge was assigned the label of negative, and, crucially, equations of current in E &...
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Electrostatic force between two grains of sand with unbalanced charge placed 30 meters apart

Quote from The Feynman Lectures on Physics Volume I: To give an idea of how much stronger electricity is than gravitation, consider two grains of sand, a millimeter across, thirty meters apart. ...
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Do electrons really perform instantaneous quantum leaps?

This is not a duplicate, non of the answers gives a clear answer and most of the answers contradict. There are so many questions about this and so many answers, but none of them says clearly if the ...
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How is the envelope of a wave derived from the wave equation?

I'm reading this book about electrical properties of materials where the electron is introduced as a wave. Using the equation of a wave, they bring about the "envelope" of a wave. So here is how the ...
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What happens to the spin when photon is absorbed by an electron?

Photon is spin 1 and electron is spin 1/2, so when a photon is absorbed by an electron it is destroyed and the electron becomes excited by that amount of energy. The next moment the electron will go ...
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Are the plates of a battery really charged?

In a zinc/copper Daniell cell correct me if I am wrong : Zinc has 2 valence electrons. So it wants to get rid of them. To do so it sends them to the copper which needs 2 to complete its valence ...
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Why Bohr atom model is still being tought in high school? [duplicate]

Bohr atom model is still the textbook content of today's high school physics. We all know that the Bohr model is only suitable for single electron hydrogen atom, not suitable for other atoms. For ...
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What happens when an electron collides with an atomic nucleus?

Say an electron is shot towards an atom at such a speed that a violent collision (or just a regular collision) is unavoidable, what happens to electron and the nucleus? (Also, I'm a mere highschooler....
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How do you get max kinetic energy from photons hitting electrons?

I read if you increase the frequency then you can get the max kinetic energy and if you decrease the wavelengths you can get enough energy to knock the electron out of its atom of a gas. Is this true? ...
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Would a flow of current (of positrons) zap us?

I have read this question: Will Positron Cause flow of electricity? To your question, yes, positrons are just as good as electrons for carrying a charge. There is no difference between "...
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Why can't an electron be observed?

I was watching a show on Netflix hosted by Neil Degrasse Tyson and he mentioned that one of the fundamental particles that we know of, the electron, is something we have never even observed directly. ...
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Dependence of radial probability function on quantum numbers

I was reading the book "Quantum Physics" from Eisberg & Resnick about the expected value of the electron radial coordinate, which it defines as \begin{align} \overline{r_{nl}} = \int_{0}^{\infty}...
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Special conditions at layer F2 ionosphere

I saw this graph about the electrons density in different altitudes and difference between night and day, the difference between the 2 electron densities (day and night) decreases till 300 Km (F2 ...
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Band gap vs QM energy level gap between electron orbitals

I have read this question: What is energy band gap? What is the reason for formation of energy bands? https://en.wikipedia.org/wiki/Nuclear_shell_model If I understand correctly, the band gap (...
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Using uncertainty principal to estimate electron energy

I'm trying to estimate the energy of an electron, using the uncertainty principle. Not sure if I did it right. The problem is estimate the energy of electron confined to a .1nm box and report answer ...
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Recombination of hydrogen

Suppose a slow-moving electron and a slow-moving proton are injected into a chamber, such that the two approach each other and are likely to combine to form an atom of hydrogen. How would one ...
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What makes north pole of a magnet north pole in the first place? [duplicate]

This question might seem absurd and illogical to many. But it just popped out in my mind while I was reading about magnetism. -Like in case of charges, positive and negative charge on an atom means ...