[alancalverd]

To be more exact, I have determined the velocity of the electron at the 1s orbital to be 2.1876912636431E+06 m/s.

Based on the uncertainty principle, you cannot disprove that.

In fact the indeterminacy principle does exactly that. If you know its velocity then it must be travelling in a straight line (velocity being a vector) so it can't be located in an orbital.

[Bored chemist]

My intention when starting this thread is to find out the precise definition of temperature. We know that a system can have many forms of energy. They are often classified as kinetic and potential energy. Which category does temperature fall into?

Neither.
That's why we call it thermal energy.

[Spring Theory]

Hi @Spring Theory ,

    I don't think I've spoken to you before, welcome to the forum.

    You've said a lot of things that are interesting and quite reasonable.   There are also a few things that might be a little bit dangerous or misleading.
    Let's start by establishing the following:
1.   I'm not the definitive expert on this.
2.   As far as I'm concerned the purpose of a forum is to discuss things and ideally move people's undertsanding onwards and upwards.  For example, my own understanding of temperature has had a bit of development since reading some articles about temperature.

     So if I or other people disagree with some of the things you've said, don't worry about it too much.   We need a few more users on this forum, don't disappear.  You should be welcome to join the discussion.   

Best Wishes. 

Dangerous is for Grizzly bears. Misleading implies intentional fraud. Neither of these terms should apply to a forum discussion.

Temperature usually refers to infrared spectrum radiation intensity. Temperature is also usually defined in terms of kinetic energy. I just tied these two together elegantly.

I will contribute when I can. Thanks.

[Bored chemist]

Misleading implies intentional fraud.

Not really.

Temperature usually refers to infrared spectrum radiation intensity.

Not really.

Temperature is also usually defined in terms of kinetic energy.

Not really.

[Origin]

To be more exact, I have determined the velocity of the electron at the 1s orbital to be 2.1876912636431E+06 m/s.

@Spring Theory, how did you determine that?

[Eternal Student]

Hi.

Dangerous is for Grizzly bears. Misleading implies intentional fraud.

    It wasn't my intention to be offensive.  Please don't assume it was.   What you said might confuse and in that sense "mislead" others like the OP who asked the question "what is temperature?"  I don't think you're trying to commit fraud or anything like that.

Best Wishes.

[hamdani yusuf (OP)]

So, it is useless for things like a burger which you want to cook whole.

How thick is the burger?
It's still useful for many things else.

Why not just accept that your idea was wrong?

[Eternal Student]

Hi.

   I really don't know why burgers have become important.  I was just going to back up to some earlier posts:

Originally a quote from @hamdani yusuf , re-used in a reply from Bored Chemist:

We know that a system can have many forms of energy. They are often classified as kinetic and potential energy. Which category does temperature fall into?

 Bored Chemist replied:

Neither.
That's why we call it thermal energy.

   That's old style.   Presumably you went to school roughly when I did but you (bored chemist) presented the article about re-defining temperature, so you've got to play fair here.
    The modern definition of temperature (in Kelvin post 2019) is trying to remove the need for such oblique references as calling something "thermal energy".  It does not step around declaring what that energy is at a microscopic scale and leave it open to all sorts of possible interpretations.   Instead it embraces the notion of microscopic statistical mechanics head on.

Alancalverd replied:

Temperature is a measure of the mean kinetic energy of the molecules inside an object. It is not a measure of the kinetic energy of the whole object, or the potential energy of any stresses within it. If you input energy in such a way as to increase the mean kinetic energy of the molecules inside an object, you will increase its temperature. If you do something else, you won't.

    Which is much more in-line with the definition of temperature used in the modern Kelvin scale.
Temperature (in Kelvin post 2019) is very much meant to be a measure of the average kinetic energy of the particles of a system.   (At least for simple systems it will be.  Whether our Kinetic Theory is adequately developed to determine the behaviour of particles in all systems like solids, liquids or a gas of photons is a different question).  If you put energy into a system that doesn't change the k.e.of the particles then, as Alancalverd stated, you won't change the temperature of the system.
    However the issue remains murky:   To the best of my knowledge, the requirement for a system to be in equilibrium hasn't disappeared in the new approach to defining temperature.  If you put energy into a system (e.g. to raise electrons to an excited state or change something else about the system that might be considered as a potential energy change instead of kinetic energy change for the particles) then you must wait until an equilibrium is re-established before the system has a well defined temperature.  When the energy of the system is re-distributed and the principles like the equi-partition of energy apply, it is very likely that the average k.e. of the particles will have increased.   (I said "likely" not guaranteed to always happen, changes of state might be one example where you can put energy into a system but there is no change in temperature).

Speculation about changes of state:
The actual shared property (temperature) is the average energy per degree of freedom.

[Taken from  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4865254/  .  An article originally suggested by Bored Chemist ]

    How they (the community of scientists using the new definitions of the Kelvin scale) consider or determine temperature for systems that can show a change of state  (e.g. from gas to liquid)  should be interesting to see.  I haven't had time to look at this yet.  However, if the kinetic theory they use allows the gas to have, lets say 5 degrees of freedom (I chose 5 because that's easily explained by the models we have for a diatomic gas), while the liquid state only supports 4 degrees of freedom (which is reasonable because we assume particles in a liquid state have less freedom of movement and therefore less parameters describing their energy) then you can see that is possible for the system to have more total energy in the gas phase than the liquid phase but the   energy per degree of freedom,  i.e. the "temperature" can remain the same.  We have a possible explanation for latent heat, the system loses degrees of freedom during phase changes.
   Let's make it clear that I haven't had time to look at this yet, it just seems reasonable.   The new approach to defining a temperature scale (introduced since 2019) just wasn't in existence when I was studying thermodynamics.

Best Wishes.

[Spring Theory]

To be more exact, I have determined the velocity of the electron at the 1s orbital to be 2.1876912636431E+06 m/s.

How did you determine that.

That is a discussion for a different thread.  I don't want to detract from the point of this thread.  Sufficient to say that it is generally accepted that the electron (or its wave function) has a velocity around the proton in a hydrogen atom.

Therefore, the smarty pants response to invalidate the actual value of the velocity is unproductive to the core goal here.

[Spring Theory]

The closest you can get to absolute zero is the ground state where the electron orbits the proton in the 1S orbital. 

What's the temperature corresponding to that state?

This is a point of debate and speculation (proper for this directory).  I would consider the hydrogen atom at its ground state as absolute zero.  The next step lower would be to knock the electron off the hydrogen atom, but you're adding energy to the system.

A proton by itself still has kinetic energy (spin) and the electron by itself still has kinetic energy (spin).

Really the only other option of absolute zero would be a universe without particles or photons.

Therefore, realistically, absolute zero is hydrogen at its ground state with no other photons nearby to interact with.

[Origin]

Therefore, the smarty pants response to invalidate the actual value of the velocity is unproductive to the core goal here.

My question was how you came up with that number valid or not.
It seemed important to the the goal here since you brought it up.  If you don't want to discuss it that's fine, no reason to get worked up.

[hamdani yusuf (OP)]

This is a point of debate and speculation (proper for this directory).  I would consider the hydrogen atom at its ground state as absolute zero.  The next step lower would be to knock the electron off the hydrogen atom, but you're adding energy to the system.

Is temperature a quantized value?

[Bored chemist]

How thick is the burger?

Thicker than the penetration depth of the IR the thermometer uses.

But, like the test tubes, the answer is that "any sensible thickness of burger" will do.

[Bored chemist]

Sufficient to say that it is generally accepted that the electron (or its wave function) has a velocity around the proton in a hydrogen atom.

No.
That is not "generally accepted".
It doesn't have a velocity round the atom.
Do you realise that the Bohr model of an orbiting electron was discarded decades ago?

[Bored chemist]

The next step lower would be to knock the electron off the hydrogen atom, but you're adding energy to the system.

Make up your mind.
Stripping the electrons off hydrogen atoms is easy; you just heat them to about 10,000 K

In what way is that closer to absolute zero?

[Bored chemist]

To be more exact, I have determined the velocity of the electron at the 1s orbital to be 2.1876912636431E+06 m/s.

@Spring Theory, how did you determine that?

He multiplied c by the fine structure constant.
In fairness, he nearly explained it earlier.

This electron is traveling at 1/137 the speed of light and thus a contributor to kinetic energy.

But it isn't  the value that is under discussion.
It's the fact that the electron in a hydrogen atom doesn't have a velocity.
If it did, it would leave the atom.

[Spring Theory]

Absorbing a photon increases energy (and velocity) which results in more kinetic energy of the atom.

How does it affect the potential energy?
For comparison, to send a satellite to geostationary orbit, more energy is required, compared to sending it to Low Earth Orbit, although the orbital speed is lower.

The potential energy would be affected by the distance from nuclear in the form of charge potential.  The farther the distance, the lower the potential energy. Of course the higher velocity also means higher kinetic energy.  This means energy has to be added in the form of a photon.

To understand potential energy vs kinetic energy best, the principle of least action is required.  This principle is the basis for all generally accepted physics.  It basically states that the difference between kinetic and potential energy (the action) is minimized.

Again, I don't want to get off topic with constructing a Lagrangian and differentiating it with respect to coordinates, etc but everyone should learn this powerful concept.

[Bored chemist]

everyone should learn this powerful concept.

It certainly seems to improve self-confidence.

[alancalverd]

Is temperature a quantized value?

No.

[alancalverd]

Sufficient to say that it is generally accepted that the electron (or its wave function) has a velocity around the proton in a hydrogen atom.

Not since 1925. How old are you? 

When describing what temperature is, it is easier to think of a single hydrogen atom.

Beware! The journey to disaster begins with a single step in the wrong direction. Temperature is an ensemble statistic and is not defined for a single atom or particle. You'll add confusion by attempting to "describe" a mathematical function that has a clear definition. Two steps in the wrong direction.....

The farther the distance, the lower the potential energy.

That's the inverse of the conventional description of potential, and rather surprising coming from a spring theorist.