All Questions
Tagged with conservation-laws electrons
23
questions
-1
votes
1
answer
22
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Can impact offset of an electron on an ion affect the resulting particle velocities?
A free electron, of mass $m_e$ and velocity $v_e$ collides with an ion of mass $m_i$ and velocity $v_i$. When they recombine, a photon of exactly the ionization energy $E_i$ will be emitted, moving in ...
- 145
1
vote
2
answers
138
views
Electrons repel each other forever - why? [closed]
I.e. charge is conserved.
How? Why?
Background
I am coming here with only my intuition, and a desire to learn. My intuition "feels" that if an electron keeps on repelling other electrons, ...
- 149
5
votes
2
answers
612
views
Is the number of electrons in the universe always the same?
My teacher just said the number of electrons in the universe always stays the same, that's not how I understood weak force interactions and electron capture. Is there some rule that states that the ...
- 341
0
votes
0
answers
45
views
Value of potential difference between two charged plates
I am currently practicing Physics questions in basic electrostatics and I am confused about why my teacher is randomly assigning V (potential energy) as 0 in random sides of two parallel plates (where ...
0
votes
1
answer
78
views
Will an isolated electron dissipate in space as energy?
Will an isolated electron, if not further engaged in any interaction, dissipate in space as energy?
- 103
24
votes
8
answers
10k
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If electrons can be created and destroyed, then why can't charges be created or destroyed? [duplicate]
I read on Wikipedia that electrons can be created through beta decay of radioactive isotopes and in high-energy collisions, for instance when cosmic rays enter the atmosphere. Also, that they can be ...
- 367
1
vote
2
answers
234
views
Photon hits an electron perpendicular to its velocity, Relativity and Work?
In the phenomenon of the Compton scattering a photon can hit a free electron under any angle.
The photon can be regarded as a 'complex' of two photons one along the velocity v of the electron and ...
- 651
3
votes
1
answer
107
views
Problem with the continuity equation for an electron gas
Consider the continuity equation for an electron gas:
$$\tag{1}
\nabla \cdot\left[n(\boldsymbol{r}, t) \frac{\partial}{\partial t} \tilde{\boldsymbol{r}}(\boldsymbol{r}, t)\right]=-\frac{\partial}{\...
- 261
1
vote
2
answers
2k
views
Selections rules for spin
what do we mean by the selection rule $\Delta S=0$?
Can you give me some example for hydrogen atom?
For example if I want to go from $1s$ to $2p$ how can I calculate $S$ for $1s$ or for $2p$?
- 941
1
vote
2
answers
728
views
Neutrino "turns into" an electron?
Here: http://www.physics.usyd.edu.au/hienergy/index.php/Why_neutrinos_%22go_through_anything_and_everything%22
it mentions neutrinos turning into an electron. I also read that neutrinos are far less ...
- 2,238
0
votes
0
answers
39
views
Why are 2 gamma photons created? [duplicate]
When a positron and an electron come together they annihilate and produce 2 gamma photons
$$e^+ +e^- \rightarrow 2\gamma$$
I can understand that they must be produced in pairs to conserve momentum. ...
- 2,356
0
votes
4
answers
136
views
Can every mass obey the Newton's 3rd law?
As in, if we were able to produce a very huge amount of force on a very small body, would it push back with the same force? Given it doesn't break or disintegrate.
Like if we electromagnetically put ...
5
votes
2
answers
1k
views
Can I feed enough spin up electrons to a black hole to affect its angular momentum?
I was reading classical spin vs quantum field spin. I know spin in quantum mechanics is just a quantum number. But what happens if I try to intentionally feed many electrons all in the same spin state ...
- 13k
1
vote
1
answer
936
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Where does the momentum go when atom absorb a photon? [duplicate]
Imagine an electron around an atom absorbs a photon and becomes excited, it has now jumped to a higher orbital. At this point in time, where does the momentum of the photon goes?
- 13k
0
votes
2
answers
1k
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About collision between an electron and photon
Can the collision between an electron and photon be inelastic? How about the energy loss in the collision as binding energy and photon bond with the electron due to high-energy collisions?
- 89