A radioactive material has a half-life of 2.5 hours. The activity of a sample was measured to be 375 cps. What was the activity of the sample 6 hr, 15 min earlier?

Question

Quizplus · Accepted Answer

To find the initial activity, use the formula A = A₀ * (1/2)^(t/T), where A is the current activity, A₀ is the initial activity, t is the elapsed time, and T is the half-life. Here, t = 6.25 hours and T = 2.5 hours. Solving for A₀ gives approximately 2100 cps.

A Radioactive Material Has a Half-Life of 2