AQA Physics PHYA5 - 28th June 2016 [Exam Discussion Thread]

Just did this one now!
Robots should be controlled removing radioactive isotopes to prevent harmful particles/rays penetrating body when close.
Radioactive isotope X is a gamma emitter which requires lots of shielding due to it's long range so must be transferred to a sealed lead container immediately which absorbs enough radiation that outside the container remains at background count rate. It has a small half life meaning it's activity is very high hence it's at very high temperatures so the sealed lead container must be placed in a cooling pond to reduce activity/temperature. It should be left in cooling pond until radiation falls to background radiation.
Radioactive isotope Y is an alpha emitter with a long half life so needs to be placed in a metallic container immediately. It should then be stored underground and labelled under lock and key. Storage problems would be that the metal container mustn't deteriorate as the sample will have to be enclosed for a long time due to its long half life.

Predictions on 6 marker for Paper A?


Posted from TSR Mobile

Okay so the question asks "With reference to Figure 1, explain why fission fragments are unstable and explain what type of radiation they are likely to emit initially"

It fully depends on the elements involved. Yes it emits neutrons but generally speaking the ratio of N/Z will still be higher than its stable isotope.

A worked example: Uranium_235 splits in to Rubidium_92 and Caesium_140 as well as 3 neutrons. N/Z for uranium is about 1.55. N/Z for Cs is 1.545. Cs_133 is the only stable isotope meaning Cs has more neutrons than its stable isotope. I'm sure there's examples where what i have said don't apply but the question asks for general terms.

Everyone is worried about the 6 marker, meanwhile, there was a 7 marker in the June 2010 Medical paper...

Edit: there was also a 7 marker in the first section that year :O

heyy can someone help me with q2 of http://sciencemathsmaster.weebly.com/uploads/6/3/2/4/6324568/nuck_1.pdf?

how do they get the numbers 238.05076 – 4.00260 – 234.04357

Answers : http://sciencemathsmaster.weebly.com/uploads/6/3/2/4/6324568/nuck_1_ans.pdf

Thank youu!

That 7 marker in the first year was quite horrible.



I think it's the question. I am certain that they will provide you with the numbers in the question.

I feel like it might be determining nuclear radii

Is it just me that finds electron microscopes in turning point extremely hard to learn cuz it's so boring 😪


Posted from TSR Mobile

Okay I get you now thanksgiving clearing that up for me!
I've got one other quick question, can alpha radiation be emitted in a nuclear reactor? I think I saw it in a mark scheme, but I though uranium wouldn't decay via alpha.
Thanks again

same

Also i really hope as the gas 6 marker came up last year it wont be on this year....the wording of that was tricky....it stated it as if it is a well known experiment to find absolute zero....we were never even taught it

Also were the boubdaries so high last year due to the paper leak?...or have they been that high before

They've been that high before. Probably because there were few writing/explanation questions and quite an emphasis on the calculations.