Question

Technetium-99m is a radioactive isotope frequently employed in medical applications as a radioactive tracer. A radioactive tracer involves introducing an isotope into the body to facilitate the generation of diagnostic images for health condition assessment. Technetium-99m possesses a half-life of 6 hours. If a patient is administered a dose of technetium-99m in the morning, what approximate percentage of the technetium-99m will remain within the patient's body after 12 hours?(1 point)
Responses

12.5%
12.5%

93.8%
93.8%

6.25%
6.25%

25.0%

Answer 1

The half-life of technetium-99m is 6 hours. This means that after 6 hours, half of the technetium-99m will remain, and after another 6 hours (for a total of 12 hours), half of that remaining amount will still be present.

Let's break it down:

1. After the first 6 hours, 50% of the original dose remains.
2. After another 6 hours (which totals 12 hours), half of the remaining 50% will be left:
- 50% / 2 = 25%

Therefore, after 12 hours, 25.0% of the technetium-99m will remain within the patient's body.

The correct answer is **25.0%**.