What is the approximate half-life of Cs-137?

The half-life of Cs-137, or cesium-137, is widely accepted to be approximately 30.1 years. This means that after this period, half of a given quantity of Cs-137 will have decayed into its daughter isotope, barium-137. Understanding the half-life is crucial in radiographic testing and other applications because it helps professionals estimate how long a radioactive material remains hazardous and informs safe handling and disposal practices.

Cs-137 is a byproduct of nuclear fission processes and is used in various applications, including medical treatments and industrial radiography. Knowing its half-life aids in planning exposure limits and understanding the longevity of its radiological impact on both equipment and human safety. In contrast, the other options represent half-lives associated with different isotopes or are simply inaccurate figures for Cs-137.