If the halflife of a radioactive element is 30.0 years, how long will it take for a sample to decay to the point where its activity is 70.0% of the original value?

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Quizplus · Accepted Answer

The decay of a radioactive element follows an exponential decay model. To find the time it takes for the activity to reduce to 70% of its original value, we use the formula: $ t = \frac{t_{1/2}}{\ln(2)} \cdot \ln(\frac{1}{0.7}) $. Substituting the given half-life (30 years) into the formula gives approximately 15.4 years.

If the Halflife of a Radioactive Element Is 30