The graph shows the activity as a function of time for a radioisotope. The half-life of this particular radioisotope is approximately
A) 5 h
B) 4 h
C) 8 h
D) 20 h
E) 10 h

Question

The graph shows the activity as a function of time for a radioisotope. The half-life of this particular radioisotope is approximately
A) 5 h 
B) 4 h 
C) 8 h 
D) 20 h 
E) 10 h

Quizplus · Accepted Answer

The half-life of a radioactive substance is the time it takes for half of the original amount of the substance to decay. Looking at the graph, we can see that it takes 4 hours for the activity to decrease to half of its original value. Therefore, the half-life of this particular radioisotope is approximately 4 hours, making the answer B) 4 h.

The Graph Shows the Activity as a Function of Time