The graph shows the decay rate R as a function of the time t for three radioactive samples. Rank the samples according to their half-lives, shortest to longest.

Question

Quizplus · Accepted Answer

The half-life of a substance is the time required for half of the radioactive nuclei to decay. The shorter the half-life, the faster the decay rate. From the graph, we can see that the decay rate for sample 2 is the highest, followed by sample 1 and then sample 3. Therefore, sample 2 has the shortest half-life, followed by sample 1 and then sample 3. The correct rank order, from shortest to longest half-life, is 2, 1, 3. Therefore, the best choice is C.

The Graph Shows the Decay Rate R as a Function