Mass of Sun/stars (elemental/molecular vs. plasma)

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Discussion Overview

The discussion revolves around the mass composition of the Sun and stars, specifically addressing the nature of plasma and its relationship to elemental and molecular structures. Participants explore the definitions and characteristics of plasma in the context of astrophysical bodies, questioning how elements like hydrogen and helium are represented in a plasma state.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the mass of the Sun being primarily hydrogen and helium while also being described as hot plasma, questioning the compatibility of these concepts.
  • Another participant asserts that the atomic nuclei retain their identities in plasma, which allows for the quoted elemental abundances.
  • A subsequent reply clarifies that in a plasma, electrons are separated from nuclei, leading to a configuration of free protons and helium nuclei in an electron sea.
  • Some participants propose that the configuration of single protons in a sea of electrons can still be considered elemental hydrogen.
  • There is a suggestion that physics references should clarify terms like "hydrogen plasma" to avoid confusion regarding elemental phases of matter.
  • One participant questions the necessity of specifying "hydrogen plasma" versus simply referring to plasma, drawing a parallel to how solids are discussed in general terms without specifying the element.
  • A question is raised about whether hydrogen plasma in the Sun is ionized, leading to a confirmation that the atoms in a plasma are indeed ionized to some extent.

Areas of Agreement / Disagreement

Participants generally agree on the ionization of plasma and the elemental identity of hydrogen in this state. However, there remains some disagreement regarding the clarity of terminology in physics references and how to best describe the relationship between plasma and elemental composition.

Contextual Notes

There are unresolved questions about the definitions and implications of plasma in relation to elemental identity, as well as the adequacy of current physics references in conveying these concepts.

hollowman
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I'm confused about the mass of the Sun (and stars in general).
https://en.wikipedia.org/wiki/Sun
Wikipedia notes:
" It is a nearly perfect sphere of hot plasma..."
...and later ...
"About three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), ..."

I thought that plasma was not comprised of elements (much less molecules); rather, it's a soup of particles in that fourth state of matter.
Correct me if I'm off, of course.
So how can the Sun be mostly H/He (mass) and hot plasma?
-------------
I asked the above on another forum, and a reply was:

"The atomic nuclei retain their identities, which is what gives the elemental abundances quoted."

To which I replied:
Wiki also notes:
"In a plasma, electrons are ripped away from their nuclei, forming an electron "sea". This gives it the ability to conduct electricity."
I can buy that ...except the fact that (for H, 75% of Sun's mass) you've got single protons floatin' 'round in a sea of electrons. Not sure what nuclear identities can be made out from that confused mess, unless you're further dividing the proton's HYDROGEN identity to its quark-based substructure.
To which another member replied:
"The nuclear identity of a proton is simply "hydrogen". No need to bring quarks into it, an isolated proton and a hydrogen nucleus are just the same thing."
------
So what is plasma in the Sun? E.g., ist it simply 75% Hydrogen as free-floating protons in a sea of electrons ... followed by 2P/2N nuclei in that same sea of electrons ... etc.?

If I have single protons in a sea of electrons (but not in orbit around the proton), is that configuration elemental hydrogen?

Thanks!
 
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hollowman said:
I thought that plasma was not comprised of elements (much less molecules); rather, it's a soup of particles in that fourth state of matter.
Plasma IS comprised of elements - specifically their bare nuclei + electrons. Those are the particles making up the soup.
hollowman said:
ist it simply 75% Hydrogen as free-floating protons in a sea of electrons ... followed by 2P/2N nuclei in that same sea of electrons ... etc.?
Yes.
hollowman said:
If I have single protons in a sea of electrons (but not in orbit around the proton), is that configuration elemental hydrogen?
Yes. It's hydrogen plasma.
 
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Bandersnatch said:
Plasma IS comprised of elements - specifically their bare nuclei + electrons. Those are the particles making up the soup. Yes. It's hydrogen plasma.
Thx!
I think Wiki (and other physics references) should use compound phrases like "hydrogen plasma" and/or be more clear when it comes to defining the elemental phases of matter.
 
hollowman said:
I think Wiki (and other physics references)
Wikipedia is not a physics reference.
 
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hollowman said:
Thx!
I think Wiki (and other physics references) should use compound phrases like "hydrogen plasma" and/or be more clear when it comes to defining the elemental phases of matter.
Why? "Solid" is a state of matter, you don't have to list "iron solid, sodium solid, chromium solid, gold solid, ...". You can talk about solid gold if you want to look at this element in particular, but that is not the general concept of a solid any more - it is more specific. Same for plasma: You can make many general statements about plasma, but if you want to look at one particular instance (like the sun) you can be more specific: "hydrogen/helium plasma".
 
Is plasma, like hydrogen plasma in the Sun, ionized? Ionized by one of the word's definitions (i.e., loss of an electron)?
 
The atoms in a plasma are ionized - at least enough of them to have many electrons and ions. That is the definition of a plasma.
 

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