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September 30, 2014

September 30, 2014

Posted by **Rachel** on Saturday, May 18, 2013 at 4:06am.

a)(a) What is the half-life of the element? half-life:

b)How long will it take for a sample of 100 mg to decay to 51 mg?

time needed:

- math -
**Steve**, Saturday, May 18, 2013 at 5:08am.36 = (1/2)^(100/k)

k = 67.84

so, the half-life is 67.84 days

Makes sense, since the sample has decreased by a little more than 1/2 in 100 days.

51/100 = (1/2)^(t/67.84)

t = 65.9 days

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