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What keeps a solid together?

  1. Aug 16, 2015 #1
    I have been pondering in my mind that if mathematically a partial is made up of an uncountable infinity of space, then how do particles not dismantle and keep a solid a "solid"? This might be a confusing question so, sorry.
  2. jcsd
  3. Aug 16, 2015 #2


    Staff: Mentor

    Welcome to PF!

    The first step in getting a useful answer is to understand what you are asking so:

    Can you elaborate?

    What do you mean by a partial?

    and uncountable infinity of space?

    and keeping a solid a solid?
  4. Aug 16, 2015 #3
    Alright, so, I meant to say an atom, and by the means of an uncountable infinity of space i mean that in a number there are decimal points (as an example .01)
    and in between 0 and 1 are and infinite amount of points such as .01, .001, .0001, etc, that there is an uncountable infinite amount to what is in between 0 and 1. And what keeps the atoms together to make a solid. Correct me if I am wrong.
  5. Aug 16, 2015 #4


    Staff: Mentor

  6. Aug 16, 2015 #5
  7. Aug 16, 2015 #6


    Staff: Mentor

    Did you mean cooperation?
  8. Aug 16, 2015 #7
    Yes, sorry, I am on my phone and it auto corrected me.
  9. Aug 16, 2015 #8


    Staff: Mentor

    Yeah, I've had to turn off that feature.

    One time while texting my wife, it replaced one of my intentionally misspelled words yesssssssssss with a woman's name Jess and my wife went WHAT! ? !%#@ ?

    Its okay we're still married.
  10. Aug 17, 2015 #9


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    Science Advisor
    Education Advisor

    I don't really get the first part of your question, but solids are held together by bonds between atoms. There are several different kinds of bonds. For crystals like salt, which is composed of the positive ion Sodium and the negative ion chlorine, the solid is held together by the Coulomb force. In the other extreme of a metal, the metals essentially share a "sea" of electrons which can go between the atoms (individually). When electrons away from an atom, the ion becomes positive and has an attraction to valence electrons. A molecular solid (like ice) is an intermediate where there are individual molecules containing covalent bonds. Each atom has an oxidation number, and the bonds are made to fill the valence shells of both with the shared electrons. These molecules are held together by by intermolecular forces like the van der waals force caused by interaction of spontaneous dipole moments of molecules. A covalent solid is a solid made of covalent bonds connecting the atoms (no individual molecules).

    As for the stability and structure of these systems, you can synthesize something and it will eventually minimize its energy to find the ideal configuration. However, this doesn't have to be an absolute minima. There is something called being meta stable where the system is at a local minima, so if you somehow get the systems there, it will stay there even if you perturb it slightly. You can see this by looking at phoning modes (lattice vibrations) around the configuration.

    The thing you said about atoms having some sort of infinity of space is very misleading. Each atom is a quantum system and likewise has a wave functions. When you put atoms together you get a many body wave function. However, in a lot of these systems the wave function is localized to the site it sits on. In a metal, the positive ion cores can be approximated as stationary and the quasiparticles move around like they are free (can write eigenstates in terms of plane waves). I say quasiparticles because if there are interactions there properties could differ that those of electrons (the charge is the same but they can have a different effective mass).
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