All Questions
Tagged with electromagnetism nuclear-physics
15
questions
16
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Protons' repulsion within a nucleus
Do the protons inside the nucleus repel each other by the electrostatic force? If they do, why doesn't the repulsion drive the protons apart so that the nuclei get disintegrated?
- 273
16
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2
answers
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If the strong nuclear force is stronger than electrostatic repulsion, why don't nuclei collapse into a point?
Today in class we were discussing the strong nuclear force, and our teacher was explaining about how the strong nuclear force counteracts the repulsion force between protons in a nucleus.
When asked ...
- 183
5
votes
1
answer
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What prevents an atom's electrons from "collapsing" onto its protons? [duplicate]
Forgive me if the answer to this is obvious. I have no formal physics training, and I remember that when I asked my physics teacher this, she just frowned and said "Good question."
An electron is ...
- 251
5
votes
7
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Why can't electrons fall into the nucleus? [duplicate]
I read a book on pop sci book on quantum mechanics and the author said that electrons do not fall into the nucleus due to quantum mechanics- which principles suggest this (I think it was Heisenberg's ...
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5
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Why are heavier nuclei unstable?
If you have more neutrons than protons, then there will be more strong force present to counteract the repulsive forces between protons. Why is it that above bismuth, no nucleus is stable, regardless ...
- 1,499
3
votes
1
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Why isn't Hydrogen's electron pulled into the nucleus? [duplicate]
Possible Duplicate:
Why do electrons occupy the space around nuclei, and not collide with them?
Why don’t electrons crash into the nuclei they “orbit”?
From what I learned in chemistry, the ...
- 335
15
votes
4
answers
2k
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Do neutron stars reflect light?
The setup is very simple: you have a regular ($1.35$ to $2$ solar masses) evolved neutron star, and you shine plane electromagnetic waves on it with given $\lambda$. Very roughly, what shall be the ...
- 2,374
9
votes
2
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We know that the protons in a nucleus are positively charged. So why does the nucleus stay intact? [duplicate]
We know that the protons in a nucleus are positively charged, whereas the neutrons do not possess a charge; we also know that unlike charges attract. So why does the nucleus stay intact, even though ...
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37
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3
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Nuclear Fusion: Why is spherical magnetic confinement not used instead of tokamaks in nuclear fusion?
In nuclear fusion, the goal is to create and sustain (usually with magnetic fields) a high-temperature and high-pressure environment enough to output more energy than put in.
Tokamaks (donut shape) ...
- 495
24
votes
1
answer
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Why is a stellarator-type nuclear fusion reactor so oddly-shaped?
My first impression: It's a mess.
Why is it shaped like that? I can't find any info about its shape other than it's a special arrangement of magnetic coils.
- 528
15
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2
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Why do spin-$\frac{1}{2}$ nuclei have zero electric quadrupole moment?
Why do spin-$\frac{1}{2}$ nuclei have zero electric quadrupole moment? How does this come about, and how can one tell in general whether a spin-$j$ nucleus can have a nonzero quadrupole (or higher ...
- 3,701
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votes
3
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What causes radioactivity? Is it a quantum mechanical effect?
I'm just curious what causes radioactivity. I've been told that in the case of alpha decay, since the nucleus is quantum mechanical, there is a probability that the configuration of protons and ...
- 229
4
votes
2
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7k
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What makes a nucleus unstable?
My question is simply that - what makes a nucleus unstable? What exactly causes a nucleus to start breaking apart in the first place? Is it the Coulomb force between the neighboring protons?
I'm just ...
- 5,371
1
vote
1
answer
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Changing electromagnetic and strong coupling in tandem?
It has been widely said that if $\alpha$ were to increase by only a few percent, life would be impossible because of the lack of carbon production in stars--and if it is increased too much, ...
- 2,196
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Why could the Yukawa potential explain how protons can be bound in the nucleus?
The Yukawa Lagrangian
$$\mathcal{L}=-\dfrac{1}{4}F_{\mu\nu}F^{\mu\nu}+\dfrac{1}{2}m^2A_\mu A^\mu-A_\mu J^\mu$$
can be used to derive the equations of motion
$$\Box A_\mu=J_\mu-m^2A_\mu$$
for the ...
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