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What happens after a Photon pass-es through an element without causing any ElectronTransition? e.g. A Cube of Scanadium

Photons pass through glass all the time without causing a transition. Metals are different. Even though they don't promote a bound electron from one orbital to another, they do interact with photons. ...
mmesser314's user avatar
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Decomposition of $(x \pm i y) \, Y_{l m}$ and $z \, Y_{l m}$ on spherical harmonics

The [Wigner-Eckart] theorem was invented to solve exactly this type of problem. Especially in this case where it is difficult to find the results for some quantum number values, while for others it is ...
Jos Bergervoet's user avatar
1 vote

Atomic force is weaker than nuclear force? A terminology question

Consider the preceding words in the text: He compares the energy required to remove a nucleon from a nucleus, and then the energy required to free an electron from an atom. The force comparison is ...
mike1994's user avatar
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2 votes
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Hydrogen atom in a very strong magnetic field

The essential problem in this question is whether the electron orbit is squeezed to the center or whether it is pushed outward even to the point of becoming unbound. To answer that we can look at the ...
Jos Bergervoet's user avatar
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What is the magnetic quantum number for $p_x$, $p_y$, $p_z$?

What I have understood is that $m=0$ for $z$ is certain and can be said with certainty but not for $x$ and $y$. They can have $m=+1$ or $m=-1$.
Nidhi's user avatar
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1 vote

About Quantum Mechanics at macroscopic level

LIGO is an example where quantum mechanics matters on a macroscopic scale. LIGO measures gravitational waves. These waves stretch and squeeze distances as they pass through Earth. The changes are tiny ...
mmesser314's user avatar
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About Quantum Mechanics at macroscopic level

But he states that this is not acceptable, because we don't know what is touch at macroscopic level, hence it makes no sense to explain it via microscopic level. He states that QM is valid only at ...
naturallyInconsistent's user avatar
1 vote

About Quantum Mechanics at macroscopic level

People like to say that quantum theory can't be used to explain behaviour of macroscopic systems but they can be used to explain the behaviour of atoms. This raises the problem that since you're made ...
alanf's user avatar
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Why are there selection rules in electronic transitions?

I am unsure of what type of answer and the level of answer you are looking for. If you are looking for a mathematical answer, it is because of the symmetries of functions, and the symmetry of the ...
Dr. Nate's user avatar
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4 votes

About Quantum Mechanics at macroscopic level

It has been mathematically proven that GR goes to Newton's gravity theory in the limit for small masses and small velocities. Also it has been mathematically proven that in the limit for even smaller ...
Fred. Zwarts's user avatar
1 vote

Where can I find data about hyperfine levels of a given atom?

As far as I am aware, astronomers are the biggest users of hyperfine structure parameters. Knowing this, I found the Vienna Atomic Line Database (VALD3). Here is a list of their hyperfine data. This ...
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Why do atoms absorb photons?

First of all, electromagnetic waves are relatively well-coupled to electric charges. The coupling strength is given by something called the fine structure constant which has the value of about (1/137)....
niels nielsen's user avatar
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Why do atoms absorb photons?

In one sense, you can think of a rock that also "wants" to be at the bottom of a hill. Why does it allow you to push it up? You exert a force on the rock and give it energy. Atoms absorb ...
mmesser314's user avatar
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Most general non-relativistic Hamiltonian for hydrogenic atom in quantised electromagnetic field

I think the answer to your question is in the bound state QED formulation. If you want to go to the formulation of the bound state problem you will find it here in this paper by furry, which is an ...
Laserrager's user avatar
7 votes
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Dielectric and dipole

An atom may be neutral as a whole but its parts aren't. The electric field applies opposite forces to the negatively-charged electron cloud and the positively-charged nucleus, resulting in a net ...
Vincent Thacker's user avatar
4 votes

Dielectric and dipole

The molecule doesn't "acquire" a dipole moment from the electric field. The electric dipole moment is a measure of the separation of positive and negative charges within a system, i.e., a ...
Bob D's user avatar
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