Half-life of iodine 125 is:

The half-life of iodine-125 is an important concept in radiation therapy and nuclear medicine, as it impacts the duration and effectiveness of the isotope in various applications, such as brachytherapy for cancer treatment.

Iodine-125 has a half-life of approximately 60 days. This means that after 60 days, half of the iodine-125 present in a sample would have decayed into other substances, thus influencing the dose delivered to tissues over time.

Understanding the half-life helps in determining how frequently doses should be administered and allows for accurate planning in treatment protocols, ensuring that patients receive the appropriate amount of radiation while minimizing excessive exposure. The choice reflecting the correct half-life is critical for maintaining effective and safe treatment regimens.

In contrast, the incorrect options provide values for half-lives of other isotopes or incorrect values altogether, emphasizing the importance of knowing the specific half-life for iodine-125 in clinical and theoretical settings.