PHY1H (OLD SPEC) Unit 1 AQA GCSE

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I got technium something or other (the last one) for the irradiation as gamma wont ionise cells and also wont last very long
(short half life)

i wrote sand as 1000-250 = 850 so more was reflected.

i wrote dummy's position!! FML!!! :frown:

i also got 200 for the boiler question, i dont remember the others!

thank GOD I got one q right.. the last answer was 90 years, i got that, wahoo!! xD

could someone tell me what the answer was to the one u had to circle? i got environmental and social i think (last once to circle)

Reply 61

MichelleQ

Someone make an UNOFFICIAL MARKSCHEME please :biggrin:

Reply 62

R.P.Everything.

Just had a quick google -I think it is Cobalt 60:

http://www.epa.gov/rpdweb00/sources/food_irrad.html

Reply 63

Nikhil_m

what was the question that everyone is talking about, 0.95 x 8 = 7.6 or something what Question was this?

Reply 64

ClarkyC...

I got technitican or whatever it was..... Shortest half life so safe

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Reply 65

ClarkyC...

I think it was environment and economy cause it mentioned paying the shool

This was posted from The Student Room's Android App on my HTC Sensation XL with Beats Audio X315e

Reply 66

clare1111

But it was to do with people so wasn't it social? :/

Reply 67

ClarkyC...

Was there a social and economic because if so then it would be thst if not I'd say economy and environment because they had to pay the school to help the the environment and surroundings

This was posted from The Student Room's Android App on my HTC Sensation XL with Beats Audio X315e

Reply 68

MichelleQ

What past paper from what year was this one like?

Reply 69

maxtate

Guys definite answers -

25 was the no. of hours, 7.6 kJ was the energy, it was technetium 99, it was snow :smile:

and I put the first choice, ethical and soming :/ Dunno right answer tho

Reply 70

MichelleQ

Someone please REMIND ME OF THE TOPICS :biggrin:

Reply 71

maxtate

Original post by MichelleQ

Someone please REMIND ME OF THE TOPICS :biggrin:

Conduction/convection, half-life, satellites, EM spectrum (microwaves), red shift, forgot the rest 8-)

Reply 72

R.P.Everything.

Original post by maxtate

Guys definite answers -

25 was the no. of hours, 7.6 kJ was the energy, it was technetium 99, it was snow :smile:

and I put the first choice, ethical and soming :/ Dunno right answer tho

Are you sure it is technetium 99 used to irradiate food? The half life was only 6 hours, so it keeps needing to be replaced.

This website seems to say that Cobalt 60 is most commonly used: http://www.epa.gov/rpdweb00/sources/food_irrad.html

Which makes sense, as its half life is 5.3 years.

Reply 73

maxtate

Original post by R.P.Everything.

I asked one of our teachers LOOL :biggrin:

i put tech 99 as well tho cuz if the half life is 5.3 years e.g. for cobalt, then the food would still contain the radiation, which well...isn't good 8-) but by the time the food has been packaged etc, and after the manufacturing process, the nucleus would have decayed so it can't be harmful as the amount would be negligible.

(edited 11 years ago)

Reply 74

R.P.Everything.

Original post by maxtate

I asked my teacher LOOL :biggrin:

I'm pretty sure the radioactive material isn't put in the food itself; it's put over the food and radiation is released in beams to irradiate the food. Besides, from chemistry, anything with technetium in is highly toxic, so I doubt they would actually spray the food with that.

Can someone else confirm what the right answer is?

Reply 75

daniya12

Original post by R.P.Everything.

Anyone get cobalt 60 as the material to irradiate food with?

hmm i got technetium, cos it was gamma, so could kill bacteria, and had a shorter half life than the other gamma source so could reduce to a small, safe level much quicker

Reply 76

Nikhil_m

can someone remind me what the question was for that 7.6 KJ one? i don't remember this :/ really panicing lool :smile:

good luck for your exams btw

Reply 77

Aidanb90

It was technetium with 6 hour half-life. Penetrates the food but decays fast so food is safe.

I put ethical and economical. It was about money and ethical because is it right to be possibly endangering children with long term microwave exposure.