# Calculating time 95% of sample to decayWatch

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#1
Can someone please explain where they got 0.05 from?
Why did they take N/N0 as 0.05?

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4 weeks ago
#2
The equation uses N/N0... the fraction of the original number of nuclei that are not decayed. the maximum value of
N/N0 is 1 and that corresponds to all the original nuclei still being there (or zero having decayed)

Saying 95% has decayed is equivalent to saying 5% have not decayed
5% as a fraction is 5/100... = 0.05

it's the conversion of the proportion of remaining un decayed nuclei to decimal
1
#3
(Original post by Joinedup)
The equation uses N/N0... the fraction of the original number of nuclei that are not decayed. the maximum value of
N/N0 is 1 and that corresponds to all the original nuclei still being there (or zero having decayed)

Saying 95% has decayed is equivalent to saying 5% have not decayed
5% as a fraction is 5/100... = 0.05

it's the conversion of the proportion of remaining un decayed nuclei to decimal
Thank you
0
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