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Silly physics question.

  1. Feb 5, 2012 #1
    I know this might sound silly, but I always wonder what happens when you say, tear a paper. Do I actually rip the atoms of the paper ? If so wouldn't nuclear forces be rather weak ? The question also reminds me of hardness. What makes an object hard ? is it the arrangement of atoms ? or to be specific, the number of electrons which holds the atoms together ?

    Sorry for the multiple-question post. I had a burst stream of consciousness.

    Thank you.

  2. jcsd
  3. Feb 5, 2012 #2
    Paper is made up many interwoven 'fibers' of cellulose 'pulp'. Kind of like a t-shirt (but made of cellulose fibers).

    The cellulose fibers are just long strings of molecules. When you rip paper, it's a mix of breaking the connections between the individual molecules and unraveling them at the same time.

    You do not alter the atoms, you don't even alter the molecules.

    What makes objects hard depends on how the atoms/molecules of a thing bind together. Some bind strongly and in crystalline lattices that support allot of force before being bent/broken. It all depends on how the atoms/molecules hook up and in what shape.
  4. Feb 5, 2012 #3

    Not exactly, it does depend on packing or how well the molecules but most importantly what forces between molecules for example the force that holds molecules of hydrogen together are the weak van der walls attractions where you have unsymetric orbit of electrons causing one side of the molecule to be slightly negative and thus the other slightly positive and then these sides can attract to other molecules. Or you can have polar bonding where due to electro negativitys of atoms causing constant negative and positive sides of a molecule due to the fact that some atoms grab more electrons than others. Then you have the hydrogen bond witch is just a very strong polar bond and the strongest is covalent network like in dimond where their is just strong covalent bonding between atoms and it reapeats so dimond is just like one big molecule
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