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    GROUP VII
    Is there anyone I should remove or add? These are just points I have to include in an exam question. Not all 100% mine btw

    Reducing ability – increases
    As the halide ions become larger in size, they become stronger reducing agents.
    • Since the size of the halide ion increases, the outer electrons are further from the nucleus, and so the attraction towards the nucleus is weaker.
    • Inner electron shells shield outer shell electrons from the attractive force the nucleus
    • Therefore larger ions lose electrons more readily


    Atomic Radius – Increases
    As the atomic number increases as the group is descended, the number of electrons per atom increases. This means that...
    • As more energy levels are occupied, the atom size increases.

    Electronegativity – Decreases
    • Atoms become larger down a group. This means the outer electrons are further way from the nucleus and so the positive nuclear charge is weaker towards these outer electrons.
    • Due to an increased number of electrons (and so shells), there is extra repulsion amongst electrons, thus making it harder to attract an electron.

    Boiling Point – Increases
    The stronger the intermolecular forces of attraction, the higher the boiling point.
    • As the molecules get bigger, the strength of the van der Waals forces between the molecules increases and so the boiling point increases.

    The halogens oxidising ability – decreases
    • As the atomic radius increases, the effective nuclear charge felt by the outer electrons is reduced due to shielding by inner electrons and because the outer electrons are further away from the nucleus. This means that the halogen atoms tend to gain electrons less readily as the group is descended.
    • They therefore become less reactive.
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    (Original post by Phalange)
    GROUP VII
    Is there anyone I should remove or add? These are just points I have to include in an exam question. Not all 100% mine btw

    Reducing ability – increases
    As the halide ions become larger in size, they become stronger reducing agents.
    • Since the size of the halide ion increases, the outer electrons are further from the nucleus, and so the attraction towards the nucleus is weaker.
    • Inner electron shells shield outer shell electrons from the attractive force the nucleus
    • Therefore larger ions lose electrons more readily


    Atomic Radius – Increases
    As the atomic number increases as the group is descended, the number of electrons per atom increases. This means that...
    • As more energy levels are occupied, the atom size increases.

    Electronegativity – Decreases
    • Atoms become larger down a group. This means the outer electrons are further way from the nucleus and so the positive nuclear charge is weaker towards these outer electrons.
    • Due to an increased number of electrons (and so shells), there is extra repulsion amongst electrons, thus making it harder to attract an electron.

    Boiling Point – Increases
    The stronger the intermolecular forces of attraction, the higher the boiling point.
    • As the molecules get bigger, the strength of the van der Waals forces between the molecules increases and so the boiling point increases.

    The halogens oxidising ability – decreases
    • As the atomic radius increases, the effective nuclear charge felt by the outer electrons is reduced due to shielding by inner electrons and because the outer electrons are further away from the nucleus. This means that the halogen atoms tend to gain electrons less readily as the group is descended.
    • They therefore become less reactive.
    I think your answers are fine. I know this may sound silly but for the trend questions just learn the markscheme off by heart. The marks are always allocated for the same answers and even if you write a long paragraph, if you don't mention the words they want, you will not get the marks. Also by only putting the points they want, you are not wasting time by repeating yourself as you're writing many points which may as well result in you losing the points they want. The marks are rewarded for specific words/phrases and even if you put them in bullet points it's fine.
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    (Original post by Phalange)
    GROUP VII
    Is there anyone I should remove or add? These are just points I have to include in an exam question. Not all 100% mine btw

    Reducing ability – increases
    It is more common to refer to as oxidising properties. As let say, F- is already negatively charged, for it to gain another electron to form F2-, that is just unfavourable, it is the same for I-, hence you don't get I^(2-). If however you say oxidising properties decreases down the group, that means Cl- displace Br2 and I2 from their halides. Br- can displace I2 but not Cl2 because of this properties.
    As the halide ions become larger in size, they become stronger reducing agents.
    • Since the size of the halide ion increases, the outer electrons are further from the nucleus, and so the attraction towards the nucleus is weaker.
    • Inner electron shells shield outer shell electrons from the attractive force the nucleus
    • Therefore larger ions lose electrons more readily


    Atomic Radius – Increases
    As the atomic number increases as the group is descended, the number of electrons per atom increases. This means that...
    • As more energy levels are occupied, the atom size increases.
    Down a group, for main group elements, effective nuclear charge increases as there are more electrons per atom, but the increase in n, the principal quantum number which indicates the energy levels occupied also increases. Overall, IE decreases down Gp VII, if IE decreases, size must get bigger as atomic radius is bigger

    Electronegativity – Decreases
    • Atoms become larger down a group. This means the outer electrons are further way from the nucleus and so the positive nuclear charge is weaker towards these outer electrons.
    Electronegativity is the ability of an atom/ion to attract to another electron. We are talking about let say H-F, F is more electronegative therefore slightly negative charge builds up on it. You can't do electronegativity arguments on F- alone, with their protons and electrons.

    • Due to an increased number of electrons (and so shells), there is extra repulsion amongst electrons, thus making it harder to attract an electron.This is electron affinity not electronegativity

    Boiling Point – Increases
    The stronger the intermolecular forces of attraction, the higher the boiling point.
    • As the molecules get bigger, the strength of the van der Waals forces between the molecules increases(because?)and so the boiling point increases.

    The halogens oxidising ability – decreases (as above, either one will explain the other one quite obviously)
    • As the atomic radius increases, the effective nuclear charge felt by the outer electrons is reduced due to shielding by inner electrons and because the outer electrons are further away from the nucleus. This means that the halogen atoms tend to gain electrons less readily as the group is descended.
    • They therefore become less reactive.
    Hope that clears the confusion
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    (Original post by algérie_mon_amour)
    I think your answers are fine. I know this may sound silly but for the trend questions just learn the markscheme off by heart. The marks are always allocated for the same answers and even if you write a long paragraph, if you don't mention the words they want, you will not get the marks. Also by only putting the points they want, you are not wasting time by repeating yourself as you're writing many points which may as well result in you losing the points they want. The marks are rewarded for specific words/phrases and even if you put them in bullet points it's fine.
    Well the new syllabus only has like 1 or 2 years of papers which won't cover all this :s
    I'll ask my teacher but thanks anyway
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    (Original post by Phalange)
    Well the new syllabus only has like 1 or 2 years of papers which won't cover all this :s
    I'll ask my teacher but thanks anyway
    I know, because I was one of last year's 'guinea pigs' when the Syllabus had only started and there was only one specimen paper we could practise on; but if you look at past papers you'll find that most of the questions are 'doable'. Only few minor things have been added or taken out. The only thing that you may not find in these papers is 'How Science Works' which represents a small chunk of the new syllabus; but over all you can do a lot of practice from the available past papers. Anyway, I wish you all the best
 
 
 
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