The number of ¹³¹I (half-life of 8.04 days) nuclei necessary to produce an activity of 5.0 mCi is A) 8.91 * 10¹⁴. B) 1.85 * 10¹⁴. C) 3.09 * 10¹². D) 5.01 * 10⁶. E) 5.01 * 10³.

Question

Quizplus · Accepted Answer

The correct answer can be found using the formula for activity (A) of a radioactive sample, which is A = λN, where λ is the decay constant and N is the number of nuclei. The decay constant λ can be calculated from the half-life (T_1/2) using the formula λ = ln(2)/T_1/2. Given the half-life of 8.04 days and the desired activity of 5.0 mCi, one can calculate the necessary number of nuclei, converting units where necessary. The specific calculations and constants lead to the answer in choice B, indicating the correct number of nuclei to achieve the given activity.

The Number of 131I (Half-Life of 8

The Number of ¹³¹I (Half-Life of 8