If we have a single electron and a single proton, Can Classical Mechanics and/or Quantum Mechanics explain why the electron revolves around the proton and not the proton around to electron?
33065
I was wondering why electrons orbited protons rather than protons orbiting electrons.  My first thought was that it was due to the small amount of gravitational attraction between them that would cause the orbit to be very close to the proton (or nucleus). The only other idea that I would have is that the strong interaction between protons and neutrons have something to due with this.  I have heard that the actual answer is due to something in QM, but haven't seen the actual explanation. The only relation to QM that I can think of is that due to a proton's spin and the fact that they are fermions, the atomic orbitals should be somewhat similar. Do protons have the same types of orbitals, that are just confined by the potential of the strong force?  A related question that came up while thinking of this being due to a gravitational interaction: do orbits between protons and electrons have a noticeable rotation between each other (as the sun orbits the earth just as the earth orbits the sun), or is any contribution this has essentially nullified by the uncertainty of the location of the electron (and possibly proton as well)?
38884
Despite being overall near-netural, I would expect the individual electrons and proton to radiate long EM waves as we accelerate around the Sun or rotate around our poles. Is the acceleration so small that the radiated energy is miniscule?  Or is it that somehow the macroscopic neutrality prevent radiation? If this is so, what mechanism causes single electrons or nuclei to fail to radiate?
122698
I'm working off the article, . I think it's well-written, but I'm not convinced about this part:     So what is causing the change in the particle’s behaviour?      In the example given above, when electrons are fired at a fluorescent screen, when we bombard the electrons with photons the interaction changes the state of the system catastrophically as, despite lacking mass, photons do carry momentum.   Here the author strongly implicates the momentum of photons as being responsible for the collapse. But is that correct to say?  I have read that the  verified that obscuring which-way information restores wave-like behavior. So it feels to me it's more about some "outer" state (perhaps well-characterized as "information") that we don't yet understand that collapses the system, not per se the photon-electron interaction.  Or am I wrong, and in fact for example, the process of obscuring in the quantum eraser experiments somehow "undoes" the photon-electron interaction or restores the quantum state through another interaction?
4258
Suppose we have an atom. It is commonly said that because of the PEP, two electrons can't be in the ground state unless they have opposite spins, because no two electrons can have the same wavefunction.  What bugs me is that spin up and spin down aren't the only possible spin states. There's a whole continuum of linear combinations of them, and as far as I can tell the PEP wouldn't exclude the possibility of having lots of electrons, all sharing the same spatial wavefunction but with different combinations of $\mid\uparrow \rangle$ and $\mid\downarrow\rangle$. Why doesn't this happen?
31105
The identification of an electron as a particle and the positron as an antiparticle is a matter of convention. We see lots of electrons around us so they become the normal particle and the rare and unusual positrons become the .  My question is, when you have made the choice of the electron and positron as particle and anti-particle does this automatically identify every other particle (every other fermion?) as normal or anti?  For example the proton is a particle, or rather the quarks inside are. By considering the interactions of an electron with a quark inside a proton can we find something, e.g. a conserved quantity, that naturally identifies that quark as a particle rather than an antiparticle? Or do we also just have to extend our convention so say that a proton is a particle rather than an antiparticle? To complete the family I guess the same question would apply to the neutrinos.
53679
It's an old-new question (I found only one similar question with unsatisfactory (for me) answer: )  It's strange for me how all books simply pass by such an important question, and mentioning strange and mathematically unsupported reasons such as:   orbits are stationary (while as I know this is just idealization, there is no stationary orbits in reality even for Hydrogen)  electrons are actually not localized due to uncertainty principle, thus they have no acceleration (while obviously in a non-spherically symmetric orbits a kind of "charge acceleration distribution" always exist) vacuum fluctuations play a major role (according to QED).   I'm not interested in how Bohr or Schroedinger explained it, I want to see a rigorous proof with QM, QED or maybe even the standard model as whole. I would like to see how this question was closed.
122010
Two electrons, or an electron and a proton, interact with each other because of the Coulomb potential, which can also be seen in the Schrödinger equation (which is the equation that describes the motion for elementary particles).  But how do an electron and a photon interact? Why can a photon kick up an electron to a higher atomic orbital, or why is a photon emitted when an electron jumps down to a lower orbital? A photon do not have any charge, so the interaction cannot be caused by the Coulomb potential. So what is it that causes the interaction, and how does that affect the Schrödinger equation? (Or well, the relativistic version of the Schrödinger equation, since we're dealing with photons.)
38443
The video  argues that almost all the mass that we are made of doesn't come interaction with the , but rather that most of a nucleus's mass comes from the space between quarks (the ).  If the video is correct, then there really needs to be an easy-to-understand explanation for mass because science popularizers make us laypeople think that the Higgs mechanism is responsible for all the mass in the atoms and that would be of course very misleading.
91409
So, I was thinking about the Bohr model of atom and I started to wonder how we could find the magnetic field due to a revolving electron (produced at the location of proton)  of hydrogen atom in first orbit.  Example:- How to find the magnetic field due to a revolving electron of hydrogen atom in first orbit? Given h ~$ 6.625*10^{-24} $;charge of electron~$1.6*10^{-19}$; $pi~ 3.141$; mass of electron~ $9.10*10^{-31}$.
53198
It is known that there are no diproton or dineutron nuclei.  Does this mean that two protons or neutrons are not actually attracted to each other? Even if the attraction was weak, wouldn't it cause bound states anyway?  Related:
40666
Quantum mechanics allows us to describe a particle as a wave, and also a collection of particles, which a car happens to be. What separates a typical wave from a classical particle is that the position is not well defined for a wave.  I think that it is hard to tell exactly how big an atom is, because the electron of the atom may be anywhere, but the probability of finding the electron gets very small as you look far away from the nuclei. I think in some sense the atom is as large as we want, depending on the definition.  When a car drives past me, is the position of the car separate from my position in a quantum mechanical way, or is it correct to say that "part" of the car hit "part" of me? I understand that no matter the answer the force from the hit is so small that it is negligible in every way, but that is not the core of the question.  In addition, if I made any wrong claims, please correct me, thanks in advance.
17930
We, as high school students have been taught that-because Bohr's model of an atom assigns specific orbits for electrons-that it is better than Rutherford's model. But what Rutherford failed to explain was why electrons don't emit EM waves &amp; fall into the nucleus. I don't see how the introduction of 'atomic orbitals' overcame this defect. Can't it still radiate EM waves?
58531
My knowledge of atomic dynamics is a little superficial. But to my understanding an electron travels an orbital path around a nucleus of an atom. "correct?" So let's say that if a hydrogen atom were to travel "extremely close to" the speed of light (relative to some laboratory system). With the electron circling the proton approximately already traveling "extremely close to" the speed of light, how is it that the electron can circle the proton without exceeding light speed? (or does it continue to orbit at all?)
16655
I am sorry if this question is silly; it′s just one of those things I wished I asked before leaving university.  If there were a static universe only as big as the size of two particles, say electrons, and there were one electron in it going back and forth from point A to point B: would time also go back and forth in the future (point B) and in the past (point A), or would it be considered to  go forward as it does for us? would it be possible to know how long that electron stayed at point A or point B, would it even make sense to ask? I guess what I am asking is: does time move forward only because there are so many particles moving in this enormous space that it is almost impossible they would all be back in the same position they held at least once before relative to each other? does time exist only as a consequence of a lot of particles and their position relative to each other, and the space for them, just like heat?
22936
So, I was reading Atom: Journey Across The Subatomic Cosmos by Isaac Asimov in order to better understand quantum mechanics when I came across this sentence:      The electron couldn't spiral into the proton because it couldn't take up an orbit with a length less than a single wave.    I was wondering why that is? Why can't an electron not have non-whole number wavelengths in atomic energy levels?
117161
A hydrogen nucleus consists of a single proton. A 2-hydrogen (deuterium) nucleus consists of a proton and a neutron. A tritium nucleus consists of a proton and two neutrons. This makes me wonder how an atomic nucleus made of a proton and a &quot;minus one neutron&quot; would look like, and the closest thing to a &quot;minus one neutron&quot; I can imagine is an antineutron.  What happens if we combine a proton and an antineutron? Are things like this even possible? If such a thing is an atomic nucleus, can we add an electron and get an atom?  Edit: in the comments below, I also asked this more specific question (I suppose it's useful to also mention it here in order not to create a complete chaos):  If the proton and antineutron annihilate, is it still possible that the thing they annihilate to remains somehow stable enough to behave like an atomic nucleus?
41831
My question might sound convoluted but my mind is twisting right now so my apologies in advanced.   Why is it that when I have one proton and one electron it is Hydrogen a clear flammable gas, and when I have say, twelve, it is carbon the driving force of life as we know it and then we end up with 239 and we have uranium a radioactive element.   How does the amount of protons affect what matter will be? Why does the amount of these particle things magically make one thing air and another cyanide?  If I have one pebble it is a pebble, if I have 13 its just more of the same pebbles. What makes protons different?  Sorry this is so convoluted,  any reply is appreciated