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    What is the difference between a substance with a giant covalent structure and asimple covalent structure?
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    (Original post by 0zero0)
    What is the difference between a substance with a giant covalent structure and asimple covalent structure?
    In what terms? There are quite alot of differences...
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    giant covalent normally refers to something like graphite or diamond. millions of atoms bonded together with covalent bonds

    a simple (or discrete) could refer to many gases for example, like CO2 which have a few covalent bonds and weak intermolecular bonds
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    (Original post by cptbigt)
    In what terms? There are quite alot of differences...
    all of them but generalised
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    (Original post by 0zero0)
    What is the difference between a substance with a giant covalent structure and asimple covalent structure?
    Yeah, as mentioned above, both are covalent structures, so we are talking about molecules rather than lattice/ions here.

    Giant molecular structure, like graphite, diamond, silicon(IV)oxide, means there are lots of covalent bonds, one might be weak, but there are so many of these bonds in a giant structure, that strengthens the whole molecule, difficult to melt/break, hence high mp/bp

    Simple covalent molecule, like sulphur exists as S8(the 8 should be a subscript) and i think phosphorous exists as P5. These are not giant molecular structure, so the amount of covalent bonds they have mean easy to be overcome at the right temperature, hence low bp/mp.

    Essentially, the structures are different due to their relative sizes.
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    (Original post by shengoc)
    Yeah, as mentioned above, both are covalent structures, so we are talking about molecules rather than lattice/ions here.

    Giant molecular structure, like graphite, diamond, silicon(IV)oxide, means there are lots of covalent bonds, one might be weak, but there are so many of these bonds in a giant structure, that strengthens the whole molecule, difficult to melt/break, hence high mp/bp

    Simple covalent molecule, like sulphur exists as S8(the 8 should be a subscript) and i think phosphorous exists as P5. These are not giant molecular structure, so the amount of covalent bonds they have mean easy to be overcome at the right temperature, hence low bp/mp.

    Essentially, the structures are different due to their relative sizes.
    Red phosphorus is P4 - which is probably what you're thinking of.
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    (Original post by cpchem)
    Red phosphorus is P4 - which is probably what you're thinking of.
    Hmm, is there no P5?
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    http://en.wikipedia.org/wiki/Allotropes_of_phosphorus
 
 
 
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