Tuesday

October 21, 2014

October 21, 2014

Posted by **John** on Saturday, November 25, 2006 at 2:13pm.

For 87.5% decomposition 1/8 is left.

(1/8) = (1/2)^3

Three half lives is the answer

Fot 99.999% decomposition, 10^-5 is left.

Solve 10^-5 = (1/2)^n for the number of half-lives, n. Take the log of each side of the equatiuon for a quick solution.

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