At the end of 40 hours, 6.25% of the original radionuclide is present in a sample. What is the half-life of the radionuclide?

Question

Chemistry

Dominic Thomas

8 May, 21:31

At the end of 40 hours, 6.25% of the original radionuclide is present in a sample. What is the half-life of the radionuclide?

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Answers (1)

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Carlie Neal · Answer 1

Work backwards. Double the percentage until it reaches 100%. How many times did you have to double it? Divide 40 by the number of times you had to double it.

Like so:

6.25---> 12.5---> 25---> 50---> 100

So you doubled it 4 times, then divide 40/4 = 10 hours. So half life is 10 hrs.