Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange
Join us in building a kind, collaborative learning community via our updated Code of Conduct.

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.

0
votes
1answer
43 views

Electric fields and insulators

Will the electric field of an induced dipole in an insulator match the electric field inducing it but in the opposite direction? I have 2 counter theories: Let's say I place an insulator (and let's ...
1
vote
1answer
56 views

Why is the drift velocity directly proportional to the electric field?

If I double the electric field, that should double the acceleration of electrons inside the conductor in the general direction of the electric field. But why does that double the drift velocity, and ...
0
votes
0answers
22 views

How would we calculate the magnitude of the electric field of a battery? [on hold]

For a battery with a given voltage, how would we calculate the electric field? Thanks!
4
votes
2answers
39 views

How do surfaces give out sound by friction, when its said that bodies dont actually touch?

So due to electron-electron repulsion, isnt it true that surfaces dont really 'touch'? If so, then how do two things rubbing each other give out sound due to friction? or is that because the uneven ...
0
votes
0answers
12 views

Cathode rays magnetic field [duplicate]

My question is regarding the fact that magnetic field is generated only by moving charge and it can act only on charged moving particles. So if we have two cathode rays one, by the other and its ...
0
votes
1answer
22 views

Can atoms capture beta particles or secondary electrons into their orbits and become anions?

Since beta-particles are just free-moving electrons, shouldn't they be caught by strongly-electronegative atoms and thus create anions? Why do they instead create more cations by knocking other ...
0
votes
0answers
21 views

estimating number of electrons available for conduction [on hold]

I've been asked to estimate the number of electrons in a metal, and the number of electrons available for conduction. I don't want to use proper Fermi-Dirac or anything, I just want an easy way to ...
0
votes
1answer
29 views

Can someone give a simple mathematical explanation of the tight binding method?

I'm trying to understand the tight binding method but I'm struggling with a lot of the mathematical formalism. A lot of the mathematical formalism I read jumps into explaining it a few too many steps ...
0
votes
1answer
67 views

Endless electron-positron annihilation/creation?

We start the process with gamma rays collision that produces positron electron pair, the pair then annihilates when hit each other and gamma rays are produced again and everything repeats. Sure, in ...
1
vote
1answer
27 views

Even/odd number of electrons per primitive cell and conductivity

In this pdf it says Because the number of electron states in a Brillouin zone is twice the number of primitive cells in a Bravais lattice (the factor two comes from spin), the zone can be ...
0
votes
1answer
34 views

Why there is no charge within the conductor even if the charges are static?

"When excess charge is placed on a solid conductor and is at rest, it resides entirely on the surface, not in the interior of the material. �" Source: University physics 13th edition p(736). ...
2
votes
0answers
34 views

Does an electron have a frequency (and hence an energy)?

The formulation is provocative, the question is similar to the question here. There I can follow the question, but not the answers, which for me imply that an electron in a momentum eigenstate does ...
1
vote
0answers
23 views

Speed of electron and proton in electric field

Speed of electron and proton in electric field. In a uniform electric field E, the acceleration of an electron in vacuum is 1836 times that of a proton (proton/electron mass ratio is 1836). I'll like ...
0
votes
1answer
112 views

Is the right-handed electron really an $SU(2)$ singlet?

In the Standard Model, neutrinos are assumed to be massless, and the right-handed neutrinos thus do not exit. Is this the reason that the right-handed electron is regarded as an $SU(2)$ singlet? ...
0
votes
0answers
37 views

Is it possible to calculate the energy level of a ground state of an electron?

All throughout my homework the lowest electron level (ground state) is never referred to as a number. Is it possible to calculate it numerically? I have wondered this because a question asked "what ...
0
votes
3answers
161 views

Newbie question: Atom identity. How can you talk about two electrons if electrons are identical? [closed]

How can you talk about two electrons if they are identical (indistinguible)? Does it make sense to let an electron to have an identity by itself? If they are on diferent places the place they are is ...
2
votes
2answers
44 views

Shouldn't the frequency increase the current in the photoelectric effect [duplicate]

I know that intensity determines the no. of electrons and the current produced. But if the intensity is constant and the frequency changes, the kinetic energy of the photoelectrons changes, so their ...
0
votes
1answer
25 views

Shouldn't intensity increase the stopping voltage in the photoelectric effect?

More intensity means more number of electrons so more probability of there being energetic electrons reaching the collecting plate so the stopping potential should technically be more. But all the ...
5
votes
3answers
104 views

Is there any “singlet state” for 3 or more spin 1/2 particles?

Every system with $N$ or more electrons lies in a Hilbert space $H=H_{\text{space}} \otimes H_{\text{spin}}$, with $H_{\text{space}}=H_{\text{space}}^{1}\otimes\cdots\otimes H_{\text{space}}^{N}$ and $...
14
votes
5answers
469 views

At an atomic level, what happens when you connect two batteries in series so that their voltages are added?

I can't for the life of me figure this out. I feel like i'm missing some crucial detail about how batteries work. Imagine two batteries connected in series, like this: ...
-1
votes
2answers
40 views

Relativistic energy level shift from $s$ to $d$ orbitals

I have read this question: This question is not about the energy levels, negative and kinetic, why it is lower (more negative) close to the nucleus. I understand those. I understand electrons have ...
0
votes
0answers
32 views

Triplet states and the Hund's rule in identifying the ground state configuration (open shell)

I referred to some of the questions about Hund's rule on StackExchange, such as this for example, but still wasn't able to have my question resolved. (the wikiepdia page has $E_{ex} = C - \frac{1}{2}...
-1
votes
2answers
59 views

If electricity is made up of electrons, how can it cause the hydrogen spectrum to appear?

The hydrogen spectrum appears when an electron absorbs a photon, jumps an orbital, and then releases that photon in an effort to get back to its ground state. From what I've read electricity is ...
3
votes
1answer
49 views

Why do thermal hotspots in a metallic nanoparticle do not match it's optical hotspots?

I am a little bit confused here. When a metallic nanoparticle is impinged with light at its resonance, the electric field is greatly enhanced at the surface along the polarisation of the wave(suppose ...
0
votes
1answer
21 views

question regarding wikipedia page on pulsed electron paramagnetic resonance

Here, under the subtitle 'principle,' it describes what happens when you have a static magnetic field along the z axis, $ B_0 \hat{z}$ and microwave field parallel to the $x$ axis, $ B_1 \hat{x}$. I ...
0
votes
1answer
25 views

Helium's first excited state (anti-symmetry of the spatial function)

Here, it's explained why, for the first excited state of He, one electron is in 1S orbital and the other electron is in 2S orbital with both spins pointing in the same direction (triplet) What I am ...
0
votes
1answer
73 views

Can charge move without accelerating?

According to Wikipedia : "An electric potential (also called the electric field potential, potential drop or the electrostatic potential) is the amount of work needed to move a unit positive charge ...
0
votes
2answers
51 views

Will the em wave oscillated by antenna 300MHz AC with 1 V amplitude voltage, have a higher energy, than same antenna config., but with 200 V, and why? [closed]

The DC voltage source provides electrons moves in a single direction, with a single speed( current($I$) shows how much electrons goes through conductor cross-section, hence from the Omh law voltage ...
0
votes
2answers
71 views

What do the arrows on this Feynman diagram represent? [duplicate]

The picture follows the convention of the time axis being on the vertical direction. I think this Feynman diagram represents Coulomb repulsion between two electrons with a virtual photon being ...
6
votes
0answers
53 views

Electric dipole moment of electron: about what point is the moment taken?

There is a lot of experimental research activity into whether the electron has an electric dipole moment. The electron, however, has a net charge, and so its dipole moment $$ {\bf \mu}= \int ({\...
0
votes
1answer
44 views

How electrons really revolve around nucleus through nodal plane in $p$ orbital? [duplicate]

I have read somewhere that electrons revolve around the nucleus and electrons are most probably found in orbitals. Can someone explain how electrons really revolve around nucleus through nodal plane ...
2
votes
5answers
232 views

Why does an electron have spin? [duplicate]

An electron is assumed to be a point particle that does not have structure and volume. Why does it have spin? Does this imply that the electron has volume? It is hard to imagine that a point (without ...
-1
votes
1answer
84 views

Why does an electron have left-handed and right-handed components? [duplicate]

An electron is assumed to be a point particle that does not have structure. Why does it have left-handed and right-handed components? Does this imply that the electron has structure or volume?
0
votes
1answer
26 views

Do the concentration of electrons in a circuit affect the magnetic field?

Beware that I am going to make a few statements and not all if any of them are necessarily true or possible. I do not know whether my premises or my main question makes sense. Assume that an AC-coil ...
0
votes
1answer
57 views

How to conduct the electron double slit experiment

I am planning to conduct the electron double slit experiment for a project in my school. Even after researching quite a bit online, I wasn't able to find a proper guide that explains the materials and ...
-1
votes
0answers
11 views

Does the inner light escape from the skin effect, which induced by other lights?

When the light incidents on the metal surface without the plasmon effect, the skin effect occurs. Will this skin effect shield another light from metal inside? If so, how can I estimate the shielding ...
1
vote
1answer
36 views

Point particle with a magnetic dipole?

I have read these questions: Are contravariant basis vectors and basis 1-forms identical? Where John Rennie's answer says that electrons do have an electric dipole moment and we imagine that in math ...
1
vote
1answer
27 views

From a QED perspective, where is an electron on the surface of a charged conducting sphere before it is detected?

Classically, charges on a charged sphere is distributed on the surface as to minimize energy (and distribute like charges as far apart as possible). But in QED a single electrons has a probability ...
0
votes
2answers
102 views

Virtual particle in QFT can destroy electron? [closed]

Electron in quantum field theory can be destroyed by virtual electron positron pair ?
1
vote
2answers
140 views

Why are photo electrons emitted instantly from metal surface just nanoseconds after the light falls upon it?

Why are photo electrons emitted instantly from metal surface just nanoseconds after the light falls upon it? How does the quantum theory of radiation explain it? Why can't classical physics explain ...
-1
votes
1answer
88 views

Permanent magnet's magnetic field arises due to the magnetic dipole moment of the electrons inside the magnet?

THIS QUESTION IS NOT A DUPLICATE OF THIS: Real QM cause of magnetic dipole moment Because that question asks about the cause of the magnetic dipole moment of an electron. This question is asking ...
1
vote
1answer
60 views

Do the wires having AC current emit EM waves? [duplicate]

When ac current is passed through a wire, the electrons in the wire oscillate to and fro in the wire (due to change in polarity of current in the wire). If the ac current is of frequency, say 50Hz, ...
1
vote
1answer
111 views

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 ...
0
votes
0answers
28 views

Historically how it was discovered that we need fields to describe matter? [migrated]

This question is from one historical perspective. The question is: how physicists historically found out that one needs quantum fields to describe matter? Being more detailed. Let us consider the ...
1
vote
1answer
78 views

Real QM cause of magnetic dipole moment

I have read these questions: Relation between magnetic moment and angular momentum -- classic theory Why is the electron magnetic moment always parallel to the spin for an electron? Does a magnetic ...
3
votes
1answer
80 views

In a material, how does the heat equation arise from phonons? And from electrons?

What would be the starting point to derive the heat equation in a material? Generally, in insulators the heat is mediated via phonons while in metals (conductors), electrons are the main responsible ...
0
votes
2answers
70 views

If $2p$ is circular, why is $2p_x$ not circular and what does $x$ mean?

I was reading about atomic orbitals. From Bohr's model, electron orbitals are considered circular. But as I saw the sub-orbitals like $2p_x$, $3d_{x^2-y^2}$ I noticed something strange. These sub-...
1
vote
2answers
51 views

How are electrons in a circuit doing work?

When electrons flow through a circuit, I don't understand how we can hook something up to the circuit (like a bulb or anything else) and have it receive power / do work. Most tutorials gloss over ...
0
votes
0answers
51 views

Could the electron count as a force-carrying particle?

Pretty straight-forward this one. If we're going to get a bit more nit-picky about this relatively straight-forward question I'd like to first of all point out that yes, I have considered that ...
-1
votes
1answer
41 views

How to determine the distance an electromagnetic field extends from a wire? [closed]

Basically I would like to figure out how far and electromagnetic field extends from a wire with a certain amount of current running through it. If I remember correctly, magnetic fields extend forever ...