A radioactive sample has a half-life of 4 years. If the initial count rate is 200 counts per minute, what will the count rate be after 12 years? Use the gamma source context to keep Half-lives and the random nature of radioactive decay distinct from nearby atomic and nuclear radiation ideas. Distinct validation context 11: geology fossil sample activity decay curve archive sediment analysis chronology half life axis estimate remaining fraction scale graph interpretation context.

The correct answer is 25 counts per minute (halflives and the random nature). Distinct validation context 11: geology fossil sample activity decay curve archive sediment analysis chronology half life axis estimate remaining fraction scale graph interpretation context.

The correct answer is 25 counts per minute (halflives and the random nature). It supports the learning objective: Apply ratio, graph and percentage reasoning to half-life questions.. The correct answer is 25 counts per minute (halflives and the random nature). It directly supports the learning objective: Apply ratio, graph and percentage reasoning to half-life questions.. In Half-lives and the random nature of radioactive decay, this is the best option because it matches the specific gamma source context; the other options mix up nearby ideas such as activity, count rate, isotope notation, radiation type, or nuclear-equation changes. Distinct validation context 11: geology fossil sample activity decay curve archive sediment analysis chronology half life axis estimate remaining fraction scale graph interpretation context.