The half-life of a radioactive isotope is 1.0 minute. In an experiment, the number of decay events was monitored in 1-minute intervals over a 5-minute period. What would you predict for the most likely observations if 50 decay events were observed in the first minute? In the second minute, ________ events were observed, and in the last minute, ________ events were observed.

Question

Quizplus · Accepted Answer

The half-life of a radioactive isotope is the time it takes for half of the radioactive atoms to decay. Therefore, if 50 decay events were observed in the first minute, it is expected that approximately half of that amount, or 25 decay events, would be observed in the second minute. By the fifth minute, the number of decay events would have halved approximately four more times (since the first observation), leading to a significantly reduced number of decay events. The option that best fits this pattern is 25 decay events in the second minute and 3 decay events in the last minute, reflecting the exponential decay characteristic of radioactive substances.

The Half-Life of a Radioactive Isotope Is 1