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andreyandreev [35.5K]
3 years ago
8

If the half life for strontium-90 is approximately 28 years, then what is the whole life for strontium-90?

Geography
1 answer:
sveta [45]3 years ago
7 0
Set this up as

10 = 40 (1/2)t/28

and solve for t in years.

10/40 = (1/2)t/28

log(0.25) = (t/28) log(0.5)

t = 28 log(0.25) / log(0.5) years = 56 years

Test the answer:

56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
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(Hope this helps!)
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