Tritium is radioactive and decays by a first order process with a half-life of 12.5 yr. If an experiment starts with 1.00×10^{- 6} mol of tritium, how much is left after 4.5 yr.?

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Quizplus · Accepted Answer

The amount of tritium left after a certain time can be calculated using the formula for first-order decay: $N = N_0 \times (1/2)^{(t/T_{1/2})}$, where $N$ is the final amount, $N_0$ is the initial amount, $t$ is the time elapsed, and $T_{1/2}$ is the half-life. Plugging in the given values ($N_0 = 1.00 \times 10^{-6}$ mol, $t = 4.5$ years, $T_{1/2} = 12.5$ years), we find $N \approx 7.8 \times 10^{-7}$ mol.

Tritium Is Radioactive and Decays by a First Order Process