8
votes
Wrong explanation for why "electron can't exist in the nucleus"?
When are asked about why an electron cannot fall into the nucleus...
This is a common "problem" when talking about the issues with the classical picture of an electron orbiting the nucleus, ...
- 58.2k
7
votes
Wrong explanation for why "electron can't exist in the nucleus"?
Electrons do "spend time" inside the nucleus, just as they "spend time" in other spherical regions of a similar size. You can see that from the fact that the $1s$ orbital wave ...
- 28.2k
5
votes
Wrong explanation for why "electron can't exist in the nucleus"?
Everything @BioPhysicist is correct, but in addition:
Your argument is semi-classical, quantum mechanics is non-relativistic (there is no $c$ in the Schrödinger Eq.), and the problem involves ...
- 36.7k
5
votes
Quantum behavior of small atoms and molecules in a material
It is definitely not true that molecules behave in accordance with classical physics at room temperature.
I will give the most traditional example, which can be found in Chapter 40 of the Feynman ...
- 1,741
5
votes
How hot can one heat a single atom?
Heat is a thermodynamic concept, applicable to systems with large number of particles (taking Avogadro number $N_A\propto 10^{23}$ as a typical number of particle sin the system). In fact, ...
- 61.8k
5
votes
What type of atomic structure, if any, would we expect immediately after the Big Bang?
The difficulty is that the conditions in the very early universe were too extreme for even light nuclei to be stable, let alone nuclei of heavy elements. There was a short window of time in which the ...
- 57.5k
4
votes
Accepted
How Would Quantum Gravity Affect Atomic Spectra?
For a literature-based approach to an answer, consider corrections to atomic spectra due to the weak nuclear interaction, which is much stronger than gravity. Such corrections consist almost entirely ...
rob♦
- 91.9k
3
votes
Accepted
Derivation of the Classical Lifetime of Hydrogen
For precise number one would indeed need to do what you described - take into account that radiation rate depends on the radius of the orbit which is changing in time.
But the logic of the QM fathers ...
- 4,029
2
votes
Accepted
How to derive the expression for derivative couplings on using the Born-Oppenheimer expansion?
Mind the subtle difference between the notations of the forms for $\Lambda_{ji}$: in the first form, there is $\nabla^2|i\rangle$ meaning that $\nabla^2$ acts on everything to the right, while in the ...
- 2,470
1
vote
Accepted
What is free electron?
Free electrons are electrons that are not under any potential, unlike atomic electrons. Their wave functions take the form of plane waves propagating in the free space (here's a wiki page and another ...
- 729
1
vote
Accepted
Where did the time dependence go in the Jaynes-Cummings Hamiltonian?
The expression you gave for the electric field $E$ is the expression for a free field in the Heisenberg picture (or for an interacting field in the Interaction-picture) - that means it already ...
- 6,868
1
vote
Can electrons exist in a superimposed state in an atom?
do electrons in an atom always have a definite spin state.
No, each electron does not necessarily have a definite spin state, in the sense that the total electronic wave function does not always have ...
- 22.4k
1
vote
Derivation of the Classical Lifetime of Hydrogen
Some derivations (such as this one: Classical Lifetime of a Bohr Atom ) do not assume circular orbits, but instead they consider nearly circular orbits as suggested towards the end of the original ...
- 505
1
vote
Emission lines from atom (for example, neon)
To add another example to Roger V.'s answer
Low pressure sodium lamps produce a spectrally clean, brilliant orange/yellow glow discharge which comes from the so-called "d line" in the ...
- 96.6k
1
vote
Lyman and Balmer series
What you claim is not universally true. Whether we see Lyman and Balmer series lines in emission or absorption is a question of the geometry, temperature, density and the gradients of temperature and ...
- 135k
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