Starting with a sample of pure ⁶⁶Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is: A) 15 minutes B) 5 minutes C) 7 minutes D) 3.75 minutes E) 10 minutes

Question

Quizplus · Accepted Answer

The decay of 7/8 of the sample means that only 1/8 remains. This corresponds to 3 half-lives (since (1/2)^3 = 1/8). Therefore, the half-life is 15 minutes / 3 = 5 minutes.

Starting with a Sample of Pure 66Cu, 7/8 of It

Starting with a Sample of Pure ⁶⁶Cu, 7/8 of It