Iodine-123,which is used for diagnostic imaging in the thyroid,has a half-life of 13 h.If 50.0 mg of I-123 were prepared at 8:00 A.M.on Monday,how many mg remain at 10:00 A.M.on the following day?

Question

Quizplus · Accepted Answer

Using the half-life formula:

Nt = N0 * (1/2)^(t/T)

Where:
Nt = remaining amount
N0 = initial amount
t = time elapsed
T = half-life

We can plug in the values:

Nt = 50.0 mg * (1/2)^(26/13)

Note that 26 hours have elapsed from 8:00 A.M. on Monday to 10:00 A.M. on Tuesday.

Nt = 50.0 mg * 0.5^2

Nt = 50.0 mg * 0.25

Nt = 12.5 mg

Therefore, the correct answer is C) 12.5 mg.

Iodine-123,which Is Used for Diagnostic Imaging in the Thyroid,has a Half-Life