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    I recently came across a question in an exam on how to explain why NF3 has a permanent dipole. The answer was that F is more electronegative than N so it forms a pyramidal shape and the dipoles effect does not cancel out. My question is how do you identify which element is more electronegative without using the Pauline scale
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    (Original post by Hmb28)
    I recently came across a question in an exam on how to explain why NF3 has a permanent dipole. The answer was that F is more electronegative than N so it forms a pyramidal shape and the dipoles effect does not cancel out. My question is how do you identify which element is more electronegative without using the Pauline scale
    electronegativity increases as you go up the periodic table and to the right of the periodic table.. F is the most electronegative element then O and then N then Cl and so on - u just need to know the trend
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    (Original post by Hmb28)
    I recently came across a question in an exam on how to explain why NF3 has a permanent dipole. The answer was that F is more electronegative than N so it forms a pyramidal shape and the dipoles effect does not cancel out. My question is how do you identify which element is more electronegative without using the Pauline scale
    Excluding the inert gases, the further right and upward you go on the periodic table, the more electroneagtive the element. So Fluorine is more electronegative than Chlorine, and Oxygen is more electronegative than Nitrogen etc..

    Hope that general trend helps?

    Edit: It's for two reasons:
    The first and more important is that the atoms in group 7 only require one more electron to fill their outer shell, so they're much closer and more desperate to fill it than the group 6 elements with 2 spaces. This determines the right hand columns as more electronegative.
    The second reason is that smaller elements have less shells of electrons, which means the positive nucleus is much less shielded and therefore has a much stronger pull for any other electrons nearby. Think of it as wrapping a magnet in layers of paper, which mean the magnet is much weaker and won't stick to the fridge any more. That's why within those columns the elements at the top are the most electronegative.

    Sorry if this reads as patronising in any way, I just wanted to try and make it as simple as possible
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    (Original post by carrotstar)
    Excluding the inert gases, the further right and upward you go on the periodic table, the more electroneagtive the element. So Fluorine is more electronegative than Chlorine, and Oxygen is more electronegative than Nitrogen etc..

    Hope that general trend helps?

    Edit: It's for two reasons:
    The first and more important is that the atoms in group 7 only require one more electron to fill their outer shell, so they're much closer and more desperate to fill it than the group 6 elements with 2 spaces. This determines the right hand columns as more electronegative.
    The second reason is that smaller elements have less shells of electrons, which means the positive nucleus is much less shielded and therefore has a much stronger pull for any other electrons nearby. Think of it as wrapping a magnet in layers of paper, which mean the magnet is much weaker and won't stick to the fridge any more. That's why within those columns the elements at the top are the most electronegative.

    Sorry if this reads as patronising in any way, I just wanted to try and make it as simple as possible
    Thank you that solves my problem - very clear response
 
 
 
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