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    (Original post by samwillettsxxx)
    If I am struggling to realise that an molecular shape has lone pairs.. If I draw a dot and cross diagram that could help me work out if there is some right?
    Yes it would but there's easier ways to find out if you have lone pairs

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    okay serious help needed, does anyone by any chance have a list of all the key definitions and phrases etc. and their explanations. you would save my chemistry as, hopefully
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    (Original post by samwillettsxxx)
    If I am struggling to realise that an molecular shape has lone pairs.. If I draw a dot and cross diagram that could help me work out if there is some right?
    Yeah, if you're unsure as to how many bonded pairs or lone pairs there are, just draw a diagram. It might take a bit more time, but at least you can ensure marks.
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    (Original post by C0balt)
    Sodium because alkali metals always have lowest first IE in their period because biggest radius in the period, smallest nuclear charge and shielding is the same across the period
    Of the same group as you go down the group first ie decreases because bigger radius and more shielding
    So yeah sodium
    Go to sleep you're not reading the question properly lol. Which one has the lowest THIRD ionisation energy

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    (Original post by justfly)
    its Aluminium mate.

    (Original post by C0balt)
    Sodium because alkali metals always have lowest first IE in their period because biggest radius in the period, smallest nuclear charge and shielding is the same across the period
    Of the same group as you go down the group first ie decreases because bigger radius and more shielding
    So yeah sodium
    (Original post by justfly)
    someone help on (e)(iv) how do you work it out!!!!
    Lol sorry didn't read the question
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    You see when there's 2 bond pairs and 1 lone pair (bent shape) is the angle 177.5 or 117.5?
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    (Original post by samb1234)
    Go to sleep you're not reading the question properly lol. Which one has the lowest THIRD ionisation energy

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    another warning from god of exams I must read the question tomorrow
    Okay I'm off lmao
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    (Original post by lukejoshjames)
    x
    cheers mate. Why does it sometimes say F2 or CL2 molecules have van der waals instead of covalent bonds? I thought they have covalent bonds too (2 non metals)
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    (Original post by Dyl98an)
    You see when there's 2 bond pairs and 1 lone pair (bent shape) is the angle 177.5 or 117.5?
    Pretty sure it's 117.5
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    (Original post by lukejoshjames)
    Yeah, if you're unsure as to how many bonded pairs or lone pairs there are, just draw a diagram. It might take a bit more time, but at least you can ensure marks.
    Thanks
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    (Original post by Lilieeeeeee)
    I'm petrified too! I have no clue what will come up but I hope its bonding and ionisation energies! they're all i seem to understand
    I'm in the same position !! I hope so too -everything else just furbarbs my brain ! I'm praying to every deity out there for tomorrow !
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    For OCR chemistry, how can you tell whether a molecule will have permanent dipole dipole interactions or just van der waals?


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    (Original post by justfly)
    cheers mate. Why does it sometimes say F2 or CL2 molecules have van der waals instead of covalent bonds? I thought they have covalent bonds too (2 non metals)
    They have both. The covalent bonds are between atoms in the molecule, and van der Waals' are between molecules (hence being called intermolecular forces). When talking about boiling and melting points, for simple molecular structures it's the intermolecular forces you need to talk about, not the covalent bonds.
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    Please can someone help me with (ii) I'll be forever in your debt and I would send you food if I could ! Name:  image.jpg
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    Also if you have 2 bond pairs and 2 lone pairs. Do they cancel to form a linear shape?
    If not then what happens?
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    (Original post by jerseyalevel)
    For OCR chemistry, how can you tell whether a molecule will have permanent dipole dipole interactions or just van der waals?


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    If it is a polar molecule (so if it has a permanent dipole) there will be dipole-dipole interactions, but if it isn't there will be van der Waal's.
    Basically, molecules containing the same atom have van der Waals', and molecules containing different bonded atoms will have dipole-dipole interactions.
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    (Original post by soph900)
    okay serious help needed, does anyone by any chance have a list of all the key definitions and phrases etc. and their explanations. you would save my chemistry as, hopefully
    http://www.cram.com/flashcards/a-lev...nitions-690998
    https://fluencycdn.fluencycms.co.uk/..._word_list.pdf
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    (Original post by Dyl98an)
    Also if you have 2 bond pairs and 2 lone pairs. Do they cancel to form a linear shape?
    If not then what happens?
    A molecule with 2 bond pairs and 2 lone pairs would be called bent or V shaped. ie H2O

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    Why does solubility of hydroxides increase down the group ? And why does the ease of thermal decomposition of carbonates decreases down the group ?
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    (Original post by Tha Realest)
    Haha no you're not an idiot.

    Please could you draw it on paper + explain ms answer.
    Okay, well Nitrogen is in group 5 so I imagine it having like 5 bonds/electrons I dont know what to call it but anyway it has 5 of them and because NH2 ion is a negative ion, this means that N will now have 6 of these bonds/electrons.

    2 of the bonds out of the 6 will be used for the Hydrogen atoms so that means 4 bonds/electrons will remain.

    These 4 remaining bonds/electrons are drawn as lone pairs. After you have figured this out you must relate it to a shape.

    The shape that has 2 bonding pairs and 2 lone pairs is known as bent and the example for this is H20, it also has a bond angle of 104.5.

    I really hope that makes sense despite not being able to find the right terminology.


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