Final answer:
Technetium-99 will have undergone four half-lives in 24 hours, leaving approximately 0.444 ng of the original 7.1 ng dose in the patient.
Step-by-step explanation:
The subject is asking about the decay of the radioisotope Technetium-99 after a certain period, which is a concept covered by chemistry, particularly nuclear chemistry.
Technetium-99 has a half-life of 6 hours. To find out how much of a substance remains after a certain amount of time, we use the formula N = N0(1/2)^(t/t1/2), where N is the final amount, N0 is the initial amount, t is the time elapsed, and t1/2 is the half-life of the substance.
In this case, 24 hours have passed, which is 4 half-lives (since 24/6 = 4). Therefore, after 24 hours, there will be 7.1 ng (1/2)^4 = 7.1 ng (1/16), which equals approximately 0.444 ng of Technetium-99 remaining in the patient.