Radiation Safety Practice Exam

Which isotope has a half-life of 8 days?

1. Uranium-238

2. Iodine-131

3. Nickel-63

4. Americium-241

The correct answer is: Iodine-131

Iodine-131 has a half-life of approximately 8 days, which makes it well-suited for certain medical applications, particularly in the treatment of thyroid conditions. Its relatively short half-life means that it is effective in delivering a therapeutic dose while minimizing prolonged radiation exposure to the patient. In the medical field, the decay of Iodine-131 leads to the release of beta particles, which can target and destroy thyroid tissue, making it an important tool in treating hyperthyroidism and certain types of thyroid cancer. The predictable half-life allows for careful dosing and scheduling of treatments. Other isotopes listed, such as Uranium-238, Nickel-63, and Americium-241, possess significantly longer half-lives, which makes them less relevant for immediate therapeutic uses in medical contexts. Their decay processes and applications are more suited to fields like nuclear energy or industrial uses rather than acute medical treatment requiring short-lived isotopes.