Question

What is the half-life of a radioactive material if its activity is measured at 9 am and found to be only 1/16 of the original value at 5 pm?

A. 4 hours
B. 6 hours
C. 8 hours
D. 12 hours

Answer 1

The half-life of the radioactive material is 2 hours. The half-life of a radioactive material can be determined by the amount of time it takes for its activity to decrease to half of its original value.

Step-by-step explanation:

The half-life of a radioactive material can be determined by the amount of time it takes for its activity to decrease to half of its original value. In this case, if the activity of the material is only 1/16 of the original value at 5 pm, then it has undergone 4 half-lives.

Since each half-life is an equal time interval, we can calculate the length of each half-life by dividing the total time elapsed between 9 am and 5 pm (8 hours) by the number of half-lives (4). Therefore, the half-life of the radioactive material is 8/4 = 2 hours.