Carbon-11 is used in medical imaging. The half-life of this radioisotope is 20.4 min. What percentage of a sample remains after 50.0 min?

Question

Quizplus · Accepted Answer

To determine the percentage of a sample that remains after a certain amount of time has passed, we can use the following formula:

% remaining = (0.5)^(t/T) x 100

where t is the time that has passed and T is the half-life of the radioisotope.

Plugging in the values, we get:

% remaining = (0.5)^(50/20.4) x 100

% remaining = (0.5)^2.45 x 100

% remaining = 18.3

Therefore, the percentage of the sample remaining after 50.0 min is 18.3%. The best choice is (C).

Carbon-11 Is Used in Medical Imaging