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# is this right? watch

1. So, some of you might be confused by this (and i apologise if you are)because im not sure if the answer i got is directly because of the example i have or whether this ratio is the same for all isotopes and any example you use, but here goes;

if an isotope's parent (P) is at 1% than this obviously means that 99% have decayed to now daughter (D). according to the table i have in my textbook this would equate to a D/P ratio of 1:1023 or just 1023. and this in turn means 10 half lives. is this correct.

i dont know any thing about half lives/the equations etc i only have my book and this table to work from so dont worry if none of this makes any sense!

thanks
2. This should help.

http://lpc1.clpccd.cc.ca.us/lpc/hann...eEquations.pdf

I make it 6.64 half-lives.
3. (Original post by Flo_Ryder89)
So, some of you might be confused by this (and i apologise if you are)because im not sure if the answer i got is directly because of the example i have or whether this ratio is the same for all isotopes and any example you use, but here goes;

if an isotope's parent (P) is at 1% than this obviously means that 99% have decayed to now daughter (D). according to the table i have in my textbook this would equate to a D/P ratio of 1:1023 or just 1023. and this in turn means 10 half lives. is this correct.

i dont know any thing about half lives/the equations etc i only have my book and this table to work from so dont worry if none of this makes any sense!

thanks
I have used Excel to make a table showing Fraction of Isoptope against Number of half-lives and this shows that the answer is between 6 and 7 half-lives. If you draw a graph then you would be able to get a more accurate answer.

Or you could use logs.

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