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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41 views
Regarding “Holes” in bands, and Photons
So from learning Band theory, and PN Junction and such, I've learned that photons are created when "holes" are filled in a band, and this is what can create light (Isn't this how LEDs work?)
Anyways, ...
4
votes
3answers
137 views
Do electrons in multi-electron atoms really have definite angular momenta?
Since the mutual repulsion term between electrons orbiting the same nucleus does not commute with either electron's angular momentum operator (but only with their sum), I'd assume that the electrons ...
6
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2answers
144 views
Do the energy levels of electron orbitals change relativistically?
When an electron emits a photon from changing energy levels, the frequency of the photon depends on the difference between the energy levels.
But if someone is moving with respect to the atom, the ...
5
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1answer
132 views
What happens to 5 electrons on a sphere?
Let's suppose we put 5 electrons on a perfectly conducting (no resistance at all) sphere.
There's no equilibrium configuration with 5 (though there is with 2, 3, 4 or 6). So will they keep moving on ...
3
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0answers
35 views
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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0answers
38 views
frequency of the photon [closed]
If an electron is accelerated within a cathode ray tube using a voltage difference of 3000 V then what is the maximal frequency for the photon that can be radiated from the electron ?
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1answer
171 views
Elastic collisions in Franck-Hertz experiment
Looking at a Franck-Hertz experimental setup, and given a potential difference such as $4.0\ V$ which is too small to excite out the first electron orbital, the electrons moving through the tube will ...
-3
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2answers
121 views
Energy source of electrons?
I am aware that electrons are moving in an empty space so basically there is no friction to slow it down and its velocity stays the same. However where did the electron get its energy from in the ...
1
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3answers
188 views
What does a subatomic charge actually mean?
I was recently reading a popular science book called The Canon - The Beautiful Basics of Science by Natalie Angier, and it talks about subatomic particles like protons, neutrons and electrons in ...
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2answers
132 views
How does an electrical field really work?
A little bit of background information: I'm planning to write a little booklet or web page about CPU/computer architecture, basically for my own education, because we didn't cover it in depth in ...
3
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3answers
385 views
Where do electrons in electricity come from?
Where do the electrons come from when an electric generator is making electricity? Is from the air? Would a generator work in a vacuum? Electrons have mass so where would they be pulled from if ...
4
votes
1answer
182 views
How many states can a n qubit quantum computer store?
A classical computer composed of '0' or '1' transistors stores $2^n$ states.
Is it true that a quantum computer composed of '0' or '1' or '0 & 1' qubits stores $3^n$ states?
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0answers
34 views
Working out the electron mobility from the transfer rate (1/s)
I have an electric field value for a uniform structure through which an electron travels. Given that I've calculated a transfer rate (frequency) for the electron when it goes from one molecule to the ...
2
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1answer
90 views
Working out the electric field from applied energy
I have created a simulation of one electron bouncing through a 3D mesh of molecules. The electron hopping is determined by a calculation of electron transfer rate using the Marcus equation (a result ...
3
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4answers
472 views
How do electrons jump orbitals?
My question isn't how they receive the energy to jump, but why. When someone views an element's emission spectrum, we see a line spectrum which proves that they don't exist outside of their orbitals ...
3
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0answers
119 views
Electron hopping among molecules - Marcus equation
I'm running out of professors to talk to, and I need to clarify a couple of things for the sake of making a realistic model of electron travel through a mesh.
This is about calculations of electron ...
3
votes
2answers
237 views
How exactly does static discharge work?
Assume I have built up a pretty high charge by rubbing the floor or something. I want to understand these situations:
I almost always get shocked when I touch a metal doorknob with my bare hand.
I ...
2
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1answer
68 views
Ejected Electrons with 0 KE?
So I was taught that:
Kinetic Energy (of electron) = Energy (of photon) - Ionization Energy
If E(photon) = IE, then KE=0 of the electron.
What does this physically/theoretically mean?
My current ...
2
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3answers
600 views
is it possible to flow current in open circuit?
First , i don't know much about chemistry and physics. I'm just a graphic designer but i have this question in my mind. I'm sorry if this question is too basic and use 'generic' language.
As i know ...
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3answers
89 views
A problem concerning the force between currents or moving electrons
Concerning two identical wires carrying the same current (same direction, speed and magnitude), they will be attracted because of the Ampere force. But when I was in the frame moving with the same ...
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1answer
203 views
Dipole moment of the electron
I've read that there are some restrictions on the value of a possible intrinsic electric dipole possessed by the electron, but isn't the dipole value dependent on the electron's wavefunction? Assuming ...
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0answers
73 views
The Deflecting System in a Hot Cathode Ray Tube
In an HCR-Tube, the deflecting system used to deviate the electron beam is made of positively charged plates. How is this justified? If, due to some malfunction, the electron beam deflects from its ...
1
vote
1answer
64 views
How does the specific frequency of EM Radiation relate to displacing electrons from their orbits?
I've only a general grasp on how all this works, so it could be I'm asking this poorly or misunderstanding what happens. With that said:
The energy of EM radiation is a function of its frequency. ...
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0answers
111 views
Research in Quantum Physics [closed]
I am Suvankar, a student of engienering. My branch is Electrical & Electronics Engineering. Although this is a Physics oriented website, I want to know whether it is possible to do M.Sc. after ...
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1answer
145 views
Why photons are emitted because of changes to electron behavior
Explanations I have read of why photons are emitted from atoms mention electrons being 'excited' to another energy level, and then returning to their base level, releasing a photon. I have also seen ...
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4answers
175 views
Find total energy and momentum of an moving electron in a rest frame
I have an electron moving with speed $u'$ in a frame $S'$ moving with speed $v'$ relative to a rest frame $S$.
How do I find the total energy and momentum of the electron in the rest frame $S$?
I ...
2
votes
2answers
598 views
How many photons can an electron absorb and why?
How many photons can an electron absorb and why?
Can all fundamental particles that can absorb photons absorb the same amount of photons and why?
If we increase the velocity of a fundamental ...
3
votes
3answers
159 views
What if $\gamma$-rays in Electron microscope?
I was referring Electron microscopes and read that the electrons have wavelength way less than that of visible light. But, the question I can't find an answer was that, If gamma radiation has the ...
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2answers
282 views
Is there a published upper limit on the electron's electric quadrupole moment?
I understand an electric quadrupole moment is forbidden in the standard electron theory. In this paper considering general relativistic corrections (Kerr-Newman metric around the electron), however, ...
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3answers
162 views
can I move the atom core only?
I was wondering if it is possible to move the atom core and leave behind the electrons. I can imagine that the electrons will follow the core. But what if the speed of the core is almost the same as ...
4
votes
1answer
150 views
Stability of a rotating ring of multiple electrons at relativistic speeds
There was a time when physicists where concerned about electron internal structure. The rotating ring model was one of the proposals to explain how a charge density could become stable against ...
2
votes
1answer
67 views
What does $\psi_j(r_i)$ mean?
I have a mean-field Hamiltonian for N electrons. The mean-field potential felt by electron $i$ at position ${\bf r}_i$ is given by
$V^{(i)}_{int}({\bf r}_i)=\sum_{j\ne i}|\psi_j({\bf r}_i)|^2$
I ...
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1answer
213 views
Excess charge on an insulator and conductor
So I was recently wondering what happens to the excess charge when it is placed on an insulator or conductor e.g. rubbing two objects together. I know in the conductor the electrons are free to move ...
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1answer
130 views
Units in cgs system
How do I find the dimensions of this quantity (in $cgs$)...
$$\frac{4\pi me^2}{h^2n_o^{1/3}}$$
where $m$ is the mass of electron
$e$ is the magnitude of electronic charge
$h$ ...
2
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1answer
176 views
Is Fractional quantum Hall effect proof that leptons are composite particles?
The fractional quantum Hall effect (FQHE) is a physical phenomenon in which the Hall conductance of 2D electrons shows precisely quantised plateaus at fractional values. Should this be considered ...
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0answers
63 views
Converting $q/m_e$ to $C/kg$ [closed]
I was doing some chemistry problems when I came across a question asking to find the charge to mass ratio of an electron in $q/m_e$. Then, it told me to compare what I found to the accepted value, at ...
6
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1answer
187 views
drift velocity of electrons in a superconductor
is there a formula for the effective speed of electron currents inside superconductors?
The formula for normal conductors is:
$$ V = \frac{I}{nAq}$$
I wonder if there are any changes to this ...
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1answer
83 views
Why is the anode (+) in a device that consumes power & (-) in one that provides power?
I was trying to figure out the flow of electrons in a battery connected to a circuit. Conventionally, current is from the (+) terminal to the (-) terminal of the battery. Realistically it flows the ...
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1answer
99 views
Making or Demonstrating Principle of Electron Microscope
is it possible to either demonstrate the principle or make a SEM ( electron microscope ) at home or lab as an enthusiast??
and how can i start?
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1answer
294 views
Why is it that protons and electrons have exactly the same but opposite charge? [duplicate]
Possible Duplicate:
Why do electron and proton have the same but opposite electric charge?
Doesn't it seem very curious that one is an elementary particle and the other a subatomic particle ...
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1answer
148 views
The electron jumps and lets loose photons
Where is the source of the photon.
If the photon propagates from within the electrons transit does this point to some sort of field?
Does the energy come from a boundary being broken in laymens ...
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votes
4answers
958 views
Bohr's model of an atom doesn't seem to have overcome the drawback of Rutherford's model
We, as high school students have been taught that-because Bohr's model of an atom assigns specific orbits for electrons-that it is better than Rutherford's model. But what Rutherford failed to explain ...
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1answer
169 views
Why do electrons make a Fermi sphere?
In Sommerfeld theory for metals, after determining all of the possible levels for a single electron, one says that we build up a state for a system with $N$ electrons by filling up those levels, ...
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1answer
194 views
why is total electron energy of an electron in metal negative?
In my textbook, it says that any electron bound in metals, modelled as some potential well $U$, has negative total electron energy, as shown below in the figure.
Why is the total electron energy ...
3
votes
2answers
383 views
How do electrons know that?
The current is maximum through those segments of a circuit that offer the least resistance. But how do electrons know beforehand that which path will resist their drift the least?
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2answers
236 views
A basic confusion about what is an atom
Wikipedia defines atom as
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons.
and defines electron as:
The ...
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3answers
61 views
fit funtion to the Sun electron fluxes data
I'd like to fit a function to the Sun's electrons flux data (blue dots), please note that x,y axis are in the log scale. The green dots are the "best" fit from the gnuplot program. I have taken the ...
2
votes
2answers
389 views
Is there a list of all atomic electron state transitions and the corresponding radiation emitted?
Here's a quote from Wikipedia:
As an example, the ground state configuration of the sodium atom is 1s22s22p63s, as deduced from the Aufbau principle (see below). The first excited state is ...
2
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1answer
31 views
Will an entangled idler electron induce a current in a conductor if the signal elctron's spin is measured?
I'm assuming a hypothetical setup as follows: Two labs (Alice and Bob) exist. Each has one electron of an entangled pair. At Alice, the electron travels through free space towards a magnetic field of ...
3
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2answers
298 views
Why do electrons around nucleus radiate light according to classical physics
As I navigate through physics stackexchange, I noticed Electron model under Maxwell's theory.
Electrons radiate light when revolving around nucleus? Why is it so obvious?
Note that I do not know ...
