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SQP - Multiple Choice - Q30 Last minute help please!!

ferg

Posted 30 May 2005 - 07:57 PM

I am stuck on this question hwo do you get the answer (D), it's impossible!!!! unsure.gif

dondon

Posted 30 May 2005 - 08:01 PM

Do you mean the specimen paper???

ferg

Posted 30 May 2005 - 08:07 PM

Yeh I do the one from the SQA website

dondon

Posted 30 May 2005 - 08:10 PM

Coz the answer to that one is B is it about half -life??

HatingHighers

Posted 30 May 2005 - 08:12 PM

The answer to question 30 is B.

The original isotope was the one with mass 200. After every half life its abundance halves. So, after 1 half life, it's abundance is 50%. After 2, it's 25% (which is what the graph shows).

You're told the sample is 8 days old. In this time it's had 2 half lives. So 1 half life is 4 days.


dondon

Posted 30 May 2005 - 08:13 PM

So then its probably impossible because its the wrong answer.lol laugh.gif

ferg

Posted 30 May 2005 - 08:15 PM

Sorry, I'm a bit dyslexic. I really need to read the questions (and the answers) carefully. Totally get it now. Thanks for your help!!

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