Chemistry

Problem

A sealed vial initially contains

4.0\times10^{4}

radioactive atoms of an isotope whose half-life is

12\,\text{h}

. Regulations require disposal only after fewer than

1.0\times10^{3}

atoms remain. Approximately how long, in days, must the vial be stored before safe disposal is allowed? a)

2.5\,\text{days}

1.8\,\text{days}

2.7\,\text{days}

5.3\,\text{days}