Heat and electrons

  • Thread starter bobie
  • Start date
  • #1
bobie
Gold Member
720
2

Main Question or Discussion Point

Hi,
I read that heat is the oscillation of atoms.

Is it only the nuclei that vibrate or also the electrons?
If so, how can they rotate and vibrate?
How do electrons react to heat, anyway? If a beam of electrons is rotating in a magnetic field and we heat up the container/the room, how dos that affect them?
 

Answers and Replies

  • #2
ZapperZ
Staff Emeritus
Science Advisor
Education Advisor
Insights Author
35,651
4,424
  • #3
bobie
Gold Member
720
2
Thanks for the links, I'll try to digest that.

When a radiator heats up the room, doesn't it emit EMR?, if so what produces that?

Can you please explain what happens to electrons when temperature rises?
I hope I can quote wiki without problems, I read that temperature affects speed in gas atoms/molucules:
The speed of a gas particle is proportional to its absolute temperature.
Is it the same with electrons?
 
Last edited:
  • #4
bobie
Gold Member
720
2
Hi,
I retraced some passages I read sometimes ago, I had swapped random movements with oscillations, it's wiki:

Thermal radiation occurs through a vacuum or any transparent medium (solid or fluid). It is the transfer of energy by means of photons in electromagnetic waves governed by the same laws
Thermal radiation is a direct result of the random movements of atoms and molecules in matter. Since these atoms and molecules are composed of charged particles (protons and electrons), their movement results in the emission of electromagnetic radiation, which carries energy away from the surface.
If that is true, do electrons circling around the nucleus can make random movements in the range of 10^12/14 Hz?

Thanks for your time!
 
Last edited:
  • #5
831
12
when a radiator heats up it emits infrared wavelength of the em spectrum , the lower part of the em spectrum is for lover kinetic energies also lower wavelengths the higher you go the more energetic the particles the higher the temperature also ,
you will need to supply alot more energy to something for it to emit x rays for example ,
 
  • #6
bobie
Gold Member
720
2
when a radiator heats up it emits infrared wavelength
Thanks,
but I know that in order to get EMR a charged particle must oscillate and to get infrared wavelength it must be a very fast oscillation.
I have been asking how atoms and most of all electrons circling arount the nucleus say in a crystal of iron can have random movements and how these can produce steady, high frequency radiation?
 
  • #7
1,233
17
An electron circling around the nucleus won't spontaneously emit radiation due to its inherent "circling" (which it doesn't do). We don't use classical physics when thinking about atomic structure. The electron and proton in a hydrogen atom, for example, constitutes a quantum system with many different states. Radiation is emitted and absorbed when this system changes state (when the electron changes its orbital). This is atomic/electronic emission and a totally different thing to thermal radiation. A single atom will do this.

Although more amenable to a classical approach, thermal radiation is still fundamentally a quantum process. It's just that instead of a single atom with a relatively small set of electronic states (and therefore very few absorption/emission lines), you have a huge number of nuclei in a solid lattice with a huge number of vibration states, so the thermal radiation appears as a continuous spectrum. It is the continuous transitioning between vibration states within the solid that causes the radiation, and since the energy gaps between adjacent high-energy vibration states are larger, a solid that is vibrating more (i.e. hotter) will emit higher frequency radiation.

You heat something up, you activate higher energy lattice vibration states, these states spontaneously radiate as they fall back to lower energy states, and the resulting spectral pattern is the Blackbody spectrum.
 
  • Like
Likes 1 person
  • #8
bobie
Gold Member
720
2
You heat something up, you activate higher energy lattice vibration states, these states spontaneously radiate as they fall back to lower energy states, and the resulting spectral pattern is the Blackbody spectrum.
Thanks, it's clearer now, EMR excite atoms in the lattice.
But why can't we say that the atoms in the lattice oscillate/ resonate (at infrared etc. frequency) and produce heat as well, that heat is (the result) of the oscillation of atoms?
 
  • #9
1,233
17
Heat is another word for energy, and there is energy in these vibrations. So the oscillations ARE heat. When you heat the solid up, it is the same as saying you are going to make the solid vibrate at higher energies.
 
  • Like
Likes 1 person
  • #10
bobie
Gold Member
720
2
Hi,
I read that heat is the oscillation of atoms.
So this statement is not completely wrong, just imprecise?
 
  • #11
1,233
17
I suppose it comes down to semantics, the vibrations are a form of energy, whether you call that heat or whatnot is subject to debate. It's more commonly used to describe a movement of energy, i.e. "you add heat to a solid, its energy increases.... it radiates more".
 
  • Like
Likes 1 person
  • #12
bobie
Gold Member
720
2
Can you please explain what happens to electrons in a tube or circling in a magnetig field, when temperature rises?
wiki says temperature affects speed in gas atoms/molucules:
The speed of a gas particle is proportional to its absolute temperature.
Is it the same with electrons?
Thanks a lot, mikeph, can you answer also that question?
 
  • #13
1,233
17
I'm not sure, that sounds like a plasma question and I have almost no knowledge about this area.
 

Related Threads on Heat and electrons

Top