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Reply 60
In the UV dissociation of water equation it says several stages above the arrow, what are these stages?!
Reply 61
HollyJ16
In the UV dissociation of water equation it says several stages above the arrow, what are these stages?!


The only thing I can think of are propagation stages, because the actual homolytic fission of water is initiation because radicals are formed. If I'd been asked in an exam I would have thought OH and H were perhaps products from that kind of reaction so that could be an in-between stage :confused:
This thread is brilliant! :biggrin:
just wanted to know whether anyone has the mark scheme to the Jan 2010 paper?
Thanks :wink:
Reply 64
jetmanchandi
just wanted to know whether anyone has the mark scheme to the Jan 2010 paper?
Thanks :wink:


Found this on another thread -Thanks Kooper :smile:
http://www.thestudentroom.co.uk/attachment.php?attachmentid=86187&d=1275743776
thank alot :biggrin:
hahahah
does anyone else have any questions or tips on what to even do with this Advanced Notice Article?

Also, does anyone else find it hard to remember everything for chemistry or am i the only one struggling? i dont know what to do!



dont worrry i have no idea either :frown:
hahahah
does anyone else have any questions or tips on what to even do with this Advanced Notice Article?

Also, does anyone else find it hard to remember everything for chemistry or am i the only one struggling? i dont know what to do!



dont worrry i have no idea either :frown:
this may possibly help http://www.astronomynotes.com/solarsys/s9.htm it's where the article if from :smile:
Reply 69
ok, what does reflux actually do again? so confused
Reply 70
its just the constant evaporating and condensing of a substance
HollyJ16
ok, what does reflux actually do again? so confused


Reflux is like distillation, but the only difference is that the heat goes up and back down again.



Up and back down again
Reply 72
Saluki-Sake
Heyya, thanks so much!!!!

With the last question could you also say CaCO3 -> CaO + CO2???? I thought the 'rocks' might be limestone LOL? :P I guess there are a couple different equations.


Yeah I checked my answers again and that equation was actually the first one on the list so I think you should stick to that :smile:
I know this sounds stupid, but how is deuterium represented as 21H if a hydrogen isotope is represented as 21H. I thought it would be 22H as deuterium has an extra neutron?
jetmanchandi
I know this sounds stupid, but how is deuterium represented as 21H if a hydrogen isotope is represented as 21H. I thought it would be 22H as deuterium has an extra neutron?


No, it would be 21H, because the bottom number is only the number of protons, and doesn't involve nuetronns (atomic number)
Saphire1
Yeah I checked my answers again and that equation was actually the first one on the list so I think you should stick to that :smile:

Ah, okay thankyou ^_^
cpdavis
No, it would be 21H, because the bottom number is only the number of protons, and doesn't involve nuetronns (atomic number)


ooooo, i knew there was a logical explanation to it, i feel like a complete idiot lol
that was the only thing i didn't get :p:

is everyone ready for the exam tomorrow?
Reply 77
Does anyone have the definitions? If not could you help out?
Ive tried google, but i get long winded answers.

Such as runaway greenhouse, feedback loop, positive feedback, runaway refrigerator process

Thanks :smile:
Reply 78
No! :frown:
Reply 79
NO:frown: :woo: :eek3: :eek: :confused:

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