B What takes up the empty space of an atom?

Chrisjohnson
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Please post scientific analysys like measurements.

I want to see what they measured with measuring devices.

I tried searching Google. Couldn't find any good paper on the subject. Only answers that it's empty and that it's not empty.

Always contradictions when searching on Google!
 
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The answer to the title of the thread is easy: nothing. If the space is empty, then there is nothing there.

You find different answers because physicists disagree. What we agree on is that the nucleus is a few pm in diameter, and the electrons will be found on average about 100 pm away (the electron itself is a point particle). Therefore some argue that all the space between the nucleus and where the electron would be found is empty, hence the atom is mostly made up of empty space.

Others, like me, do not like this reasoning. I personally think it is too classical. Quantum mechanically, the electron is in an orbital that is delocalized around the nucleus, and there is a reasonable probability of finding the electron anywhere over a wide area, including inside the nucleus. I prefer to see the entire space up to a few 100 pm to be occupied by electrons, hence not empty.
 
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DrClaude said:
Quantum mechanically, the electron is in an orbital that is delocalized around the nucleus, and there is a reasonable probability of finding the electron anywhere over a wide area, including inside the nucleus. I prefer to see the entire space up to a few 100 pm to be occupied by electrons, hence not empty.
This is indeed the general view of quantum chemists. See the entry ''Does an atom mostly consist of empty space?'' from my Theoretical Physics FAQ.
 
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I like that answer but it raises a few more questions for me.

I am a little bit confused on what you mean when you say the space is occupied by electrons.

Do you mean that the space has the potential for electrons to be occupying all of the space or that electrons are always occupying all of the space?

If the electrons are only occupying all the space some of the time then there would still be that 99.99999999996% empty space at all times.

If that's not what you meant could you please explain it again because I am not very good understanding these complex (for me :P) things.
 
Space is occupied by the electron field of quantum electrodynamics. The semiclassical view of an electron as a particle occupying a very tiny amount of space emerges only when an electron leaves an atom or molecule due to ionization. See the FAQ article I referred to.
 
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okay I tried to read your link you posted, it was pretty technical but I think I get it a little bit. You say that the electrons are liquid under certain circumstances and solid under other circumstances.

Where did you find this ouWhere did you find this out, do you have any papers or studies that measured this?

I'd like to read about it from an official source and discuss the implications with you guys. That sounds like fun to me
A. Neumaier said:
This is indeed the general view of quantum chemists. See the entry ''Does an atom mostly consist of empty space?'' from my Theoretical Physics FAQ.
 
Chrisjohnson said:
okay I tried to read your link you posted, it was pretty technical but I think I get it a little bit.
Chrisjohnson said:
Where did you find this out, do you have any papers or studies that measured this?

I'd like to read about it from an official source and discuss the implications with you guys.
I'm sorry to say, but these statements are contradictory. If you don't completely understand the link @A. Neumaier gave, then there is no point in going into the scientific litterature. Start by learning quantum mechanics. If you have knowledge of calculus, you can dive right in. Otherwise, start with the books of Feynman or Susskind.
 
The original papers are much more technical than the FAQ linked above. As in: if you fully understand the linked FAQ, you are years of study away from discussing the underlying publications on a professional level.
 
Chrisjohnson said:
papers or studies that measured this?
You can find some references in the FAQ article How do atoms and molecules look like? But if you already found the other FAQ article too technical you won't understand much of the literature - it is far more technical.
 
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well thanks everyone for making me feel stupid.

was my interpretation of the link correct or incorrect?

i mainly just want confirmation that what the link said is well supported by evidence.

if i take more time (something i don't have much of) then i could understand the link better, but before i do that i need to know the validity of the information's source.

i can't for the life of me find out (on google) what an "electron field" is. there are mentions of it but nothing specific. see this is why we need these forums!
 
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  • #11
Chrisjohnson said:
was my interpretation of the link correct or incorrect?
The electron field inside a molecule is like a kind of sticky glue - it is neither a fluid nor a solid. This is the closest analogy one can make on a nontechnical level if one wants to understand the answer to your question.

Chemists say - in the simplest vesion - LCAO (Linear combination of atomic orbitals) in place of sticky glue.

Chrisjohnson said:
i mainly just want confirmation that what the link said is well supported by evidence.
I gave enough references in the two articles linked to.

Chrisjohnson said:
find out (on google) what an "electron field" is.
googling for a phrase is not the way to properly learn science. Why do you think people have to study hard for many years to get their PhD in physics?

The electron field is the spin 1/2 field figuring in quantum electrodynamics, the most accurate theory we currently have. Chemists talk instead of electron clouds and chemical bonds to make it look more elementary. But technically the latter are just aspects of the former.

Chrisjohnson said:
well thanks everyone for making me feel stupid.
You are welcome. It is the subject that is difficult, independent of the person who studies it. Be prepared for a long and arduous road if you want to understand this properly. Everyone has a hard time to proceed from ignorance to knowledge.
 
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A. Neumaier said:
The electron field is the spin 1/2 field figuring in quantum electrodynamics, the most accurate theory we currently have.
https://en.wikipedia.org/wiki/Quantum_field_theory:
wikipedia said:
A QFT treats particles as excited states of an underlying physical field [...]

Quantum electrodynamics (QED) has one electron field and one photon field. [...]

Quantum field theory thus provides a unified framework for describing "field-like" objects (such as the electromagnetic field, whose excitations are photons) and "particle-like" objects (such as electrons, which are treated as excitations of an underlying electron field) [...]

the question "why are all electrons identical?" arises from mistakenly regarding individual electrons as fundamental objects, when in fact it is only the electron field that is fundamental.
 
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