# Tag Info

3

As Mitchell says in his comment, this is related to the uncertainty principle. The uncertainty principle states that if you have some system with a position $x$ and a momentum $p$ then there is an uncertainty in the position, $\Delta x$, and an uncertainty in the momentum, $\Delta p$, related by Heisenberg's uncertainty principle: $$\Delta x \Delta p ... 2 Under normal circumstances, what you are seeing is the steady state condition where the rate of absorption is equal to the rate at which energy is conducted away or radiated away again, so the material doesn't heat up. As I understand, unless a material fluoresces, the de-excitation happens in the infrared. Also, you should realize that just because a ... 0 I think the best way to understand spin is to look at it from a complete abstract point of view: do not try to find classical analogs to it. What you find when you perform experiments with electrons is that they interact with a magnetic fields as if they had an intrinsic magnetic moment with two possible values: a positive one and a negative one (loosely ... 1 It is true, you have to "rotate twice" (or by 720^\circ) to recover the original state. You can prove this in the following way. Let$$|a\rangle=|+\rangle\langle+|a\rangle+|-\rangle\langle -|a\rangle be a general ket. Consider now a rotation by a finite angle $\theta$ around the $z$ axis. I remind here that if a ket of a spin $1/2$ system is ...

1

Chemistry and physics have a lot of overlaps. This could be atomic physics too... I don't have a short explanation, but look up orbital hybridization and molecular orbital theory for a quantum-mechanical view of this. The above two should point you in a promising direction. Good luck with understanding the physics of bonding.

-2

photons can get absorbed by electrons of course! good questions for 1 and 2 it is infinte like Ron said for 3 it is more the acceleration of the elctron that emits photons. Speed is relative. But if you set up an experiment and give higher speed to some elctrons then they will some time get stonger acceleration and thus emit more photons 4- confusing ...

0

I think is a misinterpretation of the wave-particle duality. We always detect electrons as particles, but they have an associated wavefunction $\psi(\vec{x},t)$, which its square gives you the probability of finding the electron at each point. So in the double slit experiment, the wavefunction (probability wave) diffracts and you see that electrons form ...

1

The particle/wave duality at the micro framework where quantum mechanics has to be used does not describe "particles" as billiard balls, nor "waves" as energy/mass waves. Electrons when displaying "particle" properties are measured at a specific (x,y,z,t) but the values in space are indeterminate according to the Heisenberg Uncertainty Principle. The ...

0

The electron maintains the total energy $\epsilon$ that it had while inside the material. Inside the material it has some kinetic energy and some potential energy, but we don't really care exactly what those are since we know their sum. The point is, once it enters the vacuum, its total energy is still made up of kinetic and potential energy. Since the ...

1

As dmckee commented, angular momentum is barely mentioned in Bohr's revolutionary 1913 paper "On the Constitution of Atoms and Molecules" (Philos. Mag. 26 , 1). Instead, Bohr's bases his argument on Planck's hypothesis that the radiation from a quantum harmonic oscillator "takes place in distinctly separated emissions, the amount of energy radiated out from ...

9

Bohr postulated that electrons orbit the nucleus in discrete energy levels, and electrons can gain and lose energy by jumping between energy levels, giving off radiation of frequency $\nu$ according to the formula $\Delta E = E_2 - E_1 = h\nu$ where $\nu = \frac{1}{T}$, where T is the period of orbit, as in classical mechanics. Now during the transition, ...

0

Yes, photons are the interactors of electromagnetic force, so they interact with every particle that has non 0 charge or non 0 magnetic angolar momentum. That means both spin (intrinsic angolar momentum) or orbital angular momentum.

4

Yes, for example nuclei can be resonantly excited in magnetic fields with photons from the radio frequency band, like in NMR.

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