Physics

Problem

A radioactive sample initially contains

1.0\times10^{4}

nuclei of a certain isotope whose half-life is

3\,\text{h}

. Exactly after

3\,\text{h}

, the sample is injected with another

2.0\times10^{3}

nuclei of the same isotope. How many nuclei of the isotope will remain undecayed after a further

3\,\text{h}

? a)

4.5\times10^{3}

2.5\times10^{3}

3.5\times10^{3}

3.0\times10^{3}