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    Element 1st IE 2nd IE 3rd IE
    A 383 2437 3376
    B 409 2667 3881
    C 425 3065 4438
    D 502 4568 6929
    E 527 7314 11820

    From the above data which element has the largest atomic no?? Im really stuck and its a 3 marker
    btw the elements all belong to group 1
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    (Original post by tariktarkan1907)
    Element 1st IE 2nd IE 3rd IE
    A 383 2437 3376
    B 409 2667 3881
    C 425 3065 4438
    D 502 4568 6929
    E 527 7314 11820

    From the above data which element has the largest atomic no?? Im really stuck and its a 3 marker
    btw the elements all belong to group 1
    Ionisation energy decreases as the number of electron shells increases ...
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    Posted from TSR Mobile

    Can you explain it more..
    so as the ionisation energy decreases from E to A..the atomic number is increasing right because of more shells?
    But how can i word this to get all 3 marks??
    Thanks
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    (Original post by tariktarkan1907)
    Posted from TSR Mobile

    Can you explain it more..
    so as the ionisation energy decreases from E to A..the atomic number is increasing right because of more shells?
    But how can i word this to get all 3 marks??
    Thanks
    Shielding effect of inner electron shells decreases the attraction of the nucleus for the valence electron shell.
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    As previously said, as the atomic number increases down group 1, the number of electron shells increase. This means that the valence (outer) electron becomes more shielded from the protons in the nucleus. This weakens the attraction between the nucleus and the valence electron, reducing the energy required to remove it from the atom (the 1st ionisation energy). This effect is greater than the increased attraction arising from more positive charge in the nucleus.

    From the numbers you've given, it's apparent the numbers are given in the reverse order of atomic number, the element at the bottom is Lithium, and you can see that when you remove 2 electrons, you have a huge ionisation energy, because you have a single electron orbiting 3 protons, with no shielding at all.

    Hope this helps
 
 
 
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