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GCSE 21st Century Chemistry C1 C2 C3

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Original post by Lucykx
I've never been asked to calculate the mean specifically but yes they do love the interpreting graph questions! It's often comparing 2 graphs or they ask how it shows something from the graph, a little like what they put in ISA's


OMG, OCR does that, its so annoying, especially when it's not purely about science
Hi,

Would this be a correct explanation for tectonic plates and magnetic clues in rocks?

Tectonic plates are 12 giant slabs of rock, the rock is composed of the earth's upper mantle and the earth's crust. The tectonic plates can move and this can cause continents to separate. The earth's crust that forms Britain was initially found south of the equator, however due to the movement of tectonic plates, Britain is now to the north of the equator. Magnetite in rocks serves as evidence for this movement of earth's continents. When magma rises from below the solid mantle and solidifies, it magnetizes in the direction of the earth's magnetic field at the time. If the magnetism of a rock lies horizontally it means that it solidified closer to the equator and if it is perpendicular (at an angle) to the horizon then this means that it is closer to the south/north pole.
(edited 8 years ago)
Original post by naryana
Ahh thank you so much for your reply! I really appreciate it :smile:

Sound like you have a great technique! Do you find that the remaining 20 mins you have left are enough for the questions you have yet to answer ( After spending 10 mins going through questions and 30 trying to complete 90% of 6 markers)?


For me, yes - it's often quite rushed though and I'd only really advise it for core science (topics 1-3) as there are often lots of tick boxes, short sentence answers and graphs - but for the 4,5,6 I'm afraid my technique is plough through as fast as possible - the ones I can't answer straight away - screw them, move on - and then come back to them at the end!! Thank you! I'm sure as long as you just try to put down the absolute most relevant information, you'll finish in time!
Original post by 'Chris'
So you don't think it will be on fractional distillation?



Tbh, that was last years 6 marker - and unless they're sneaky :wink: Then i doubt it will be the 6 marker - not that doesn't mean you should revise it - BUT i think if it is on the paper, it will be more like "fractional distillation is the process of refining crude oil - what happens during this process, why?" so you'd have to talk about the different fractions containing different length hydrocarbon molecules - each fraction having similar length hydrocarbon chains and therefore similar boiling points because of the length of their chains and therefore the strength of their intermolecular forces of attraction and how that compares and how properties change with chain length (short chain molecules = low boiling points = gaseous at room temperature, long chain molecules = high boiling points = viscous) and then depending on if any data was supplied, how this may affect their different uses!

:smile:
Right - if any of you have the CGP core science book will y'all have a look on page 54 the fractional distillation page - do you reckon or do you actually know the different fractions --> like from refinery gas to bitumen and their order....? OR do you reckon that was just for demonstration purposes in the book?

Please and thank you - anxiety levels are soaring at the mo :wink:
Original post by iamlucy
Tbh, that was last years 6 marker - and unless they're sneaky :wink: Then i doubt it will be the 6 marker - not that doesn't mean you should revise it - BUT i think if it is on the paper, it will be more like "fractional distillation is the process of refining crude oil - what happens during this process, why?" so you'd have to talk about the different fractions containing different length hydrocarbon molecules - each fraction having similar length hydrocarbon chains and therefore similar boiling points because of the length of their chains and therefore the strength of their intermolecular forces of attraction and how that compares and how properties change with chain length (short chain molecules = low boiling points = gaseous at room temperature, long chain molecules = high boiling points = viscous) and then depending on if any data was supplied, how this may affect their different uses!

:smile:


Ah okay yeah that makes sense, thanks!
Screen Shot 2015-05-13 at 17.11.11.png

Struggling to understand this question and the answers for it.

Mark scheme says first, fourth and sixth box are correct. Can anyone explain why?
Original post by FTSE420
Screen Shot 2015-05-13 at 17.11.11.png

Struggling to understand this question and the answers for it.

Mark scheme says first, fourth and sixth box are correct. Can anyone explain why?


I agree with it being the first and the last one - that's definitely what I would have put - and thinking about it, the hydrogen does react more readily - because even in incomplete combustion it burns fully (always making water regardless - so it must be more reactive) :/
Reply 108
Haha, I think I am okay for chemistry apart from C3, only thing I know for that is hard and soft water! haha

Wish I could've done higher, but they shoved me in for foundation and told me I need top marks to get a B :/
Original post by iamlucy
I agree with it being the first and the last one - that's definitely what I would have put - and thinking about it, the hydrogen does react more readily - because even in incomplete combustion it burns fully (always making water regardless - so it must be more reactive) :/


I thought the top and bottom were correct, although I was unsure about the middle one. Thanks for the clarification, I understand now.
Reply 110
Original post by iamlucy
Right - if any of you have the CGP core science book will y'all have a look on page 54 the fractional distillation page - do you reckon or do you actually know the different fractions --> like from refinery gas to bitumen and their order....? OR do you reckon that was just for demonstration purposes in the book?

Please and thank you - anxiety levels are soaring at the mo :wink:



it's not on the specification so you don't need to learn it, however you might just wanna memorise the first top one and the last one just gives you something to talk about, :smile:
Anyone have an idea of what the 6 markers will be for C1, C2 and C3 or what topics you should definitely master
do we have to know about fullerenes? our teacher never taught us about them but they are in the cgp revision guide and i'm not sure if i have to learn them or not
(edited 8 years ago)
Does anyone think there's going to be a question on chlorination?
Reply 114
Original post by grovyle
do we have to know about fullerenes? our teacher never taught us about them but they are in the cgp revision guide and i'm not sure if i have to learn them or not



they're in the cgp revision guide?? where?? they're not in the spec :smile:
Aw I did this exam last year! Good luck guys :biggrin: You'll do great
Original post by kxylah
they're in the cgp revision guide?? where?? they're not in the spec :smile:

on the bit with the new materials?? maybe i have an old cgp revision guide...
but if they're not in the spec that's fine! i was scared i'd have to know about them
Do we have to know the various ways of disposing of PVC products e.g. recycling and energy recovery?
Original post by josaltzman
I feel pretty unprepared, to be honest. The questions in chemistry tend to throw me. You? :biggrin:

I'm Probably more unprepared , i spent all my time for biology :mad:
Original post by kxylah
it's not on the specification so you don't need to learn it, however you might just wanna memorise the first top one and the last one just gives you something to talk about, :smile:


Thank you - yet again you're a life-saver!

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