OCR 21st century science

ideas in context - hi, erm. i was just wondering if anyone knew what unit the biology pre release is (stuff about parasites i think it was?) , so that i know what unit to revise. Also, the unit for chemistry pre release would be helpful (stuff about periodic table etc). much appreciated.

Reply 1

EmmieK

im doing OCR 21st Century Science...dont get which biology your meaning but i think the chemistry one your talking bout is C5? Hope that kinda helps

Reply 2

olive*

for tomorrow
do b1 and b2 - the vaccinations and stuff.

Reply 3

milliondollarcorpse

What are you talking about? The pre-release stuff isn't in a 'unit', it's for a seperate test called 'Ideas about Science' (or Ideas in Context, something like that).

Reply 4

annab1684

yeah and that exam is tomorrow and the pre release topic is taken from another unit that we've studied.. it's one of the earlier ones I think, just flick through your textbook :smile:

Reply 5

Fiasco

Biology is B2 and I think Chemistry is C4. Hope that helps.

Reply 6

olive*

yeahh like remember physics?
they asked crap on radiation, which was from a previous unit, p3 i think?
so i bet they ask questions on vaccinations

Reply 7

danhirons

What's everyone doing for revision for the pre-seen material then?

On the chemsitry one - about tufa towers - what I find confusing is that it seems the water evaporates leaving salt crystals which then dissolve in the water to form ions and then the calcium and carbonate ions bond. However, what I'm unsure about is whether they bond inside the water or whether it's outside? Anyone help?

Reply 8

elysa

danhirons

i am pretty sure they bond inside the water, and then the water level drops which leaves the crytals on the side of the lake

had anyone looked at the specimin materail?