How much of a radioactive material with a half-life of 12,000 years is left after 36,000 years of decay?

3 answers

That is three half-lives?

first half life 1/2 remaining
second half life 1/4 remaining
third half life 1/8 remaining

amountrmaing=0riginalamount (1/2)^(t/th)

where t is time, th is halflife time.
I know I'm repeating myself, Angie; however, all of these problems can be worked with the formula I gave you and solved an example problem for you a couple of days ago. You need to learn to do these yourself instead of posting and obtaining answers from a third party. DrWLS, Bob Pursley, and I won't be with you when it comes test time.
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