The half-life of ⁹⁰Sr is 28.1 years. How long will it take a 17.7-g sample of ⁹⁰Sr to decompose to 0.18 g?

Name: The half-life of 90 Sr is 28.1 years. How long will it take a 17.7-g sample of 90 Sr to decompose to 0.18 g?
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Quizplus · Accepted Answer

The time required can be calculated using the formula for radioactive decay: $ t = \frac{t_{1/2}}{\ln(2)} \ln(\frac{N_0}{N}) $. Substituting the given values, $ t = \frac{28.1}{0.693} \ln(\frac{17.7}{0.18}) \approx 190 $ years.

The Half-Life of 90Sr Is 28

The Half-Life of ⁹⁰Sr Is 28