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

Multiple Choice

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?

A) 0.19
B) 0.60
C) 0.15
D) 2.8 × 10 ⁻³⁸
E) None of these choices are correct.