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A question on LiI. Watch

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    Hey guys, I'm wondering if Lithium Iodide forms ionic or covalent bonds?
    Li+ is small, so it has a high charge density while I- is large so it has a high polarisablity. Doesn't this cause LiI a covalent bond?
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    It forms ionic bonds, but it also has a significant covalent character. Some may even argue it forms very polar covalent bonds - it's right in the "grey area".
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    Basically in Chemistry things aren't as simple as putting into two categories as ionic or covalent.

    If you think of a spectrum with Ionic being on one side:

    Here---------------------------------------------------------------- and Covalent over here

    A molecule can be put anywhere along this line, and LiF is no exception. Which is why questions like this are sometimes quite difficult to assign on or the other. Li is a very small ion, but it's only a 1+ charge, whereas I- is a large ion, I would say it was around the middle. #Sittingonthefence
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    (Original post by haydyb123)
    Basically in Chemistry things aren't as simple as putting into two categories as ionic or covalent.

    If you think of a spectrum with Ionic being on one side:

    Here---------------------------------------------------------------- and Covalent over here

    A molecule can be put anywhere along this line, and LiF is no exception. Which is why questions like this are sometimes quite difficult to assign on or the other. Li is a very small ion, but it's only a 1+ charge, whereas I- is a large ion, I would say it was around the middle. #Sittingonthefence
    I wouldn't go with halfway, it's still a fairly ionic compound. It forms the rock salt structure in the solid phase, an indication that it is a good ionic system.
    ZnS, wurtzite has far more covalency and forms a structure which is 4 coordinate rather than 6 coordinate. The coordination number corresponds roughly to the ionic character, with CsCl forming an 8 coordinate structure.
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    Without looking anything up I would say that Iodine isn't that big so it's still reasonably ionic, but yes the bond will be quite polarised at the same time.

    I'm sure the wikipedia page for it might offer further clarity if you're unsure. But if you have a metal and a non-metal it's highly likely it's going to be ionic as far as I know anyways.
 
 
 
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