The effects of absolute zero temperature

[Hankelec]

I can visualize gas molecules, contained in a vessel, randomly bouncing into each other. As temperature increases, the collisions occur more rapidly. I suppose this also applies to liquids. I'll guess that a liquid's boiling point is where the molecular collisions become so violent that molecules are driven away from the liquid mass in the form of vapor. I assume that this bouncing or colliding action takes place in solids as well. Superconductors, although improving, are generally cooled by submersion in liquid nitrogen. My question is; does the extreme cold have any affect upon the rate at which the electrons of various atoms in a compound, travel about the atom's nucleus?

 

[Baluncore]

My question is; does the extreme cold have any affect upon the rate at which the electrons of various atoms in a compound, travel about the atom's nucleus?

Welcome to PF.
No, the electron energy is quantised and so not affected by temperature.

 

[Hankelec]

Welcome to PF.
No, the electron energy is quantised and so not affected by temperature.

Is the velocity of an orbiting electron constant?

 

[Baluncore]

Is the velocity of an orbiting electron constant?

Do the electrons have a velocity, or do they have a wave function?

The orbital energy level is determined by electrostatic forces from the nucleus and other electrons.
https://en.wikipedia.org/wiki/Atomic_orbital

 

[Hornbein]

The idea of electrons orbiting the nucleus like planets isn't really correct.

My advice is to realize that tiny quantum things like electrons have no similarity to anything familiar to us. Even calling them a "particle" shouldn't be taken all that seriously. All your preconceptions only get in the way. Just see them as some totally new weirdness. If you like, study the classic experiments to see how they behave in different situations.

Of all I've seen I like Feynman's QED the most.

 

[PeroK]

Is the velocity of an orbiting electron constant?

The electrons in an atom do not have classical orbits with well defined velocities. Instead, in QM the atom is a bound energy state of the various nucleons and electrons.

 

[Hankelec]

The idea of electrons orbiting the nucleus like planets isn't really correct.

My advice is to realize that tiny quantum things like electrons have no similarity to anything familiar to us. Even calling them a "particle" shouldn't be taken all that seriously. All your preconceptions only get in the way. Just see them as some totally new weirdness. If you like, study the classic experiments to see how they behave in different situations.

Of all I've seen I like Feynman's QED the most.

Yes, I agree that reference to an electron "orbit" is an oversimplification of an atom's structure. It does seem to be a decent representation for no more involvement than I have with the subject. My acquaintance with atomic structure pretty much ends with electrical conductors are made up of atoms with 4 or less valance electrons while insulaters have 5 or more valance electrons. Atomic absorption / emission spectrometers have a fringe relation but chemistry seems highly involved with bonding issues, which I gladly will leave for the chemist to deal with. I guess I have come to visualize an atom's structure as a centralized blob of protons and neutrons bound together surrounded by an electron "cloud." That explanation is satisfactory for most of my need to know applications. Contrary to what another member stated about electron movement being unaffected by temperature, I did hear a conflicting statement in a discussion regarding superconductors. I guess my initial outside the box notion was that if electrons were to stop traveling because of total absence of heat, then the material being chilled would most likely cease to exist. But, I will guess that at that point, so sort of entanglement becomes apparent.

 

[berkeman]

I guess my initial outside the box notion was that if electrons were to stop traveling because of total absence of heat, then the material being chilled would most likely cease to exist.

Say what?

I think @phinds has a good mantra about thinking outside the box...

 

[phinds]

I guess my initial outside the box notion was that if electrons were to stop traveling because of total absence of heat, then the material being chilled would most likely cease to exist. But, I will guess that at that point, so sort of entanglement becomes apparent.

Thinking outside the box is an admirable activity, BUT ... first you have to learn what's IN the box. On the Physics Forum, we discuss the stuff that's in the box, so you're in the right place.

 

[Bystander]

There is a difference between ground state, https://en.wikipedia.org/wiki/Ground_state , and absolute zero, https://en.wikipedia.org/wiki/Absolute_zero .

 

[sophiecentaur]

if electrons were to stop traveling because of total absence of heat,

That is really not the way to think of things. The simple kinetic theory of gases and also the behaviour of electrons in metals, which works pretty well at modest temperatures can't be extrapolated downwards because the quantum nature of everything means that the rules change.

 

[Hankelec]

Thinking outside the box is an admirable activity, BUT ... first you have to learn what's IN the box. On the Physics Forum, we discuss the stuff that's in the box, so you're in the right place.

Unfortunately physics is not a strong suit of mine. Things in the world of quantum are not second nature to me and explanations and theories sometimes appear open-ended to me. I still have to consider that math is an exact science. When it comes to a point where 1+1=3, I will try to gracefully bow out and wait for the conclusions as they come forth.

 

[PeterDonis]

if electrons were to stop traveling because of total absence of heat

They won't, because the energy associated with the electrons inside atoms or molecules has nothing to do with heat; it's the same regardless of the temperature. Heat, as you correctly describe in your OP, has to do with the atoms or molecules as a whole moving around and bouncing off each other. (And also, for molecules, with internal vibrations where the distances between the atoms in the molecule oscillate about their equilibrium positions.)

 

[TeethWhitener]

There's a lot going on in this thread. I’ll try to address some of the more confusing points.

My question is; does the extreme cold have any affect upon the rate at which the electrons of various atoms in a compound, travel about the atom's nucleus?

In a sense, kind of. At nonzero temperature, electron energy is thermally distributed just like every other degree of freedom. This explains why, in a normal, non-superconducting solid, electrical conductivity generally increases with temperature, because as you increase the temperature, you increase the average number of electrons in the conduction band. It also explains why metals are generally more thermally conductive than insulators: heat energy is carried in electron motion as well as atomic motion. Similarly, in a group of weakly interacting atoms or molecules like one finds in a gas at thermal equilibrium, the electronic energy is thermally distributed, but these energy levels are widely spaced compared to thermal energy at everyday temperatures, and the electrons are therefore overwhelmingly likely to be found in their ground energy states. This is a straightforward stat mech problem, as long as your calculator is double precision (when I said overwhelmingly, I meant it ).
Superconductors are different because their mechanism of conductivity is completely different, so we'll ignore them right now.

My acquaintance with atomic structure pretty much ends with electrical conductors are made up of atoms with 4 or less valance electrons while insulaters have 5 or more valance electrons.

No idea where you're getting this but it's not right. Carbon has 4 valence electrons, but diamond is an electrical insulator whereas graphite is a conductor.

I guess my initial outside the box notion was that if electrons were to stop traveling because of total absence of heat, then the material being chilled would most likely cease to exist.

The reason this notion is fraught is because the classical idea of "motion" doesn’t carry over cleanly to quantum mechanics. At absolute zero, where all electrons in a material are in their lowest possible energy states, the wavefunction of the system does not evolve in time in any observable way, so there's no "motion" in that sense--the electrons don't really "travel," so to speak, in any observable sense. However, electrons in a solid do occupy quantum states that have non-zero momentum, even at absolute zero. Moreover, even in an isolated atom, the quantum virial theorem applies, so that there is a non-zero average kinetic energy for electrons in an atom at absolute zero. So even though the system doesn't observably change over time, components of it have non-zero momentum and kinetic energy. Clasically, kinetic energy/momentum/system-changing-over-time are basically all synonymous with the concept of motion but quantum mechanics is more complicated. Regardless, materials don’t cease to exist at absolute zero.

 

[Frabjous]

Unfortunately physics is not a strong suit of mine. Things in the world of quantum are not second nature to me and explanations and theories sometimes appear open-ended to me. I still have to consider that math is an exact science. When it comes to a point where 1+1=3, I will try to gracefully bow out and wait for the conclusions as they come forth.

You might enjoy “The quest for absolute zero” by Mendelssohn.