The radioactive isotope tritium decays with a first-order rate constant k of 0.056 year⁻¹. What fraction of the tritium initially in a sample is still present 30 years later?

Question

Quizplus · Accepted Answer

The decay of tritium follows first-order kinetics, described by the equation $N_t = N_0 e^{-kt}$, where $N_t$ is the amount of substance at time $t$, $N_0$ is the initial amount, $k$ is the rate constant, and $t$ is the time. Given $k = 0.056 \, \text{year}^{-1}$ and $t = 30 \, \text{years}$, we can calculate the fraction remaining as $e^{-0.056 \times 30} \approx 0.19$.

The Radioactive Isotope Tritium Decays with a First-Order Rate Constant