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Formal name for molecular aggregations?

  1. Jan 19, 2018 #1
    Is there a word that describes physical bodies of molecules?
    By this, I mean any "body" that is composed of similar or different molecules, whether it is an ocean, a drop of water, a mountain, a glass cup, or a cloud, or even living bodies and their parts for that matter.

    This is in lines of: atoms build molecules, molecules build _____?

    The closest I can think of is "material" but I imagine there is got to be a more formal term? I heard a term "condensed body" but I am not sure if that''s correct.
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  3. Jan 19, 2018 #2


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  4. Jan 19, 2018 #3
    Thanks for the response Bystander!
    Is the correct term then a "state"? or "state of matter"? Sounds like "aggregation of matter" is got to be it.
    I'm hoping to find a common term for all the different states (i.e. solids, liquid,s gases, plasmas, etc)
  5. Jan 19, 2018 #4


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    The difference between "molecule" and "bulk matter" is a function of your "field of interest." Surface chemistry and adsorption, nephelometry/turbidimetry and colloids/suspensions, nano-scale you-name-it in materials science, the sky's the limit.
  6. Jan 29, 2018 #5
    Hi again, I've been looking up the term "substance" or "chemical substance" and I was wondering whether substance by definition includes "bulk matter"?
    I am a bit confused about the exact defintion of "substance". Are "elements", "molecules", "compounds" and "mixtures" and "bulk matters" all chemical substances? Or is substance defined in some other more restrictive way?
  7. Jan 29, 2018 #6
    Sorry, I might not have been clear with my question.
    I trying to understand up until which "stage" the word substance applies. I gather it applies to elements, molecules and compounds, what what about mixtures and bulk matter? Are those substances too?
    If yes, what would be the distinction between substance and bulk matter?
    Hope that clarifies it further.
  8. Jan 29, 2018 #7


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    "Yes ANNDDD no." Depends on context; a "cake mix" is not a mixture in the thermodynamic sense, since there are multiple solid phases present, but, it is still "colloquially" a mixture. How much thermo have you had?
  9. Jan 29, 2018 #8
    Yes, and would a "cake mix" be considered a "chemical substance"? And I am wanting to focus to official terminology rather than casual terms.
  10. Jan 29, 2018 #9


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    Let's start with a few "yes or no" questions. Maybe I'll be able to steer you in the correct direction(s).
  11. Jan 29, 2018 #10
    Ok, great thanks. Here they are all in order:
    Is substance a synonym for matter?
    Is substance an atom? (I guess I could reverse it and not lose meaning: is atom a substance?)
    Is substance a molecule?
    Is substance a compound?
    Is substance a mix of same atoms, molecules or compounds? (e.g. a diamond, or glass of distilled water)
    Is substance a mix of different atoms, molecules or compounds? (e.g. a cake mix) (I assume this is where its "meaning" ends, but I am not sure)

    Another way of formulating what I am trying to ask is: Clearly, substance means different things, but at which point the concept of substance doesn't apply?

    Many thanks again!
  12. Jan 29, 2018 #11


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  13. Jan 29, 2018 #12
    Thanks Ygggdrasil, super helpful!
    "A chemical substance is composed of one type of atom or molecule."
    "Chemical substances are often called ‘pure’ to set them apart from mixtures."

    Basically, substances = pure substances. That's where I think my confusion was coming from.
  14. Jun 10, 2018 #13
    I still don't think I have a convenient term for "molecular aggregations" figured out. i.e. a common term that can be used from a puddle of pure water to a living organism filled with atoms and molecules. I can use "molecular aggregation" but it sounds so clunky.

    Is "Bulk matter" the actual term?
    Mixture cannot be it, as it doesn't include pure substances.

    Any suggestions appreciated!
    Last edited: Jun 10, 2018
  15. Jun 10, 2018 #14

    jim mcnamara

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    There is no one term. And the boundaries are somewhat hazy. My approach is not the most precise. And your question is kind of all-encompassing.

    Learn about the Tyndall effect: How light scatters in colloids and very fine suspensions. It is a way to differentiate some of what you are talking about.
    Please have a look: https://en.wikipedia.org/wiki/Tyndall_effect because I use this concept below

    At one end of the "spectrum" of your topic is the solution - a solvent dissolves a solute, e.g. brine or vinegar, no Tyndall effect

    As we move onto colloids: sols, gels, and emulsions - examples are Jello gelatin desserts, mayonnaise - mayonnaise does not transmit light, but jello may show the Tyndall Effect. The components can be demulsified, for example: lye into mayonnaise and it will separate - do not eat it!.

    Suspension- a mixture of particles suspended in a fluid like air or water, wood smoke is an example, aerosols is another. Smoke shows a Tyndall effect. Suspended dust particles also show that effect - the rays of the sun.

    A mixture is one or more several different particle sizes which are mechanically separable by sieving. Or other mechanical means like vibration. And in some cases those particle size closely associate to different minerals or chemicals. Soils are the classic example. Clay particles are usually made of a few chemically bound minerals, often the phyllosilicate group.

    Terms that need better definitions --- your turn, Mr Google will help!
    soil particle sizes: loam, clay, silt, sand, gravel, channers
  16. Jun 10, 2018 #15
    That's very helpful, thanks Jim. It becomes a bit of a futility when one starts to dig too deep with terminology.
  17. Aug 4, 2018 #16
    Nevertheless, you might enjoy looking at, if only for their intrigues, the words "congery/congeries" and "conflux/confluxes", as used for what you are calling aggregration/s (static and dynamic; material and energetic) by Lucretius.
  18. Aug 5, 2018 #17
    Great! Thanks sysprog!
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