New answers tagged atomic-physics
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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How hot can one heat a single atom?
I have to begin by being pedantic. Thermodynamics (the subfield of physics where temperatures, entropy, and pressures are explained) does not make statements about the state of a single atom. Like ...
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How hot can one heat a single atom?
I'll start with question #1:
For the radiation to have any effect on the hydrogen atom, it must have a frequency (and therefore a well-defined energy content) that the atom is capable of responding to....
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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, ...
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Combination of line profiles
Suppose we sample a function $f(x)$, but our resolution possesses a finite width $\Delta$: For each point $x_0$ we do not measure $f(x_0)$, but we obtain the moving average of the function $f$ with ...
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Why does it make sense to say that "full shells" have 0 angular momentum even when not using the configuration model?
This was going to be a comment, not an answer, because I am guessing that you are happy with L and S quantum numbers for atomic hydrogen and so are happy that for n=2 there are 8 possible combinations ...
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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 ...
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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 ...
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Emission lines from atom (for example, neon)
The light emitted by a gas discharge lamp depends on pressure:
The color of the light produced depends on the emission spectra of the atoms making up the gas, as well as the pressure of the gas, ...
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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♦
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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 ...
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Ionisation of hydrogen
I remember an experiment I did with my physics teacher in high school (bac), we put hydrogen gas in a cylindrical enclosure covered with paper, in the enclosure, there are two carbon electrodes, when ...
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How is the energy of an electron-shell related to the speed of electrons in that shell?
The counter intuitive phenomenon you describe is the same in both classical and quantum systems. Objects near the earth orbit faster than objects further away. The closer orbits have higher kinetic ...
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