Student determination of the half-life of 137Ba. The radioactive barium isotope 137Ba has a relatively short half-life and can be easily extracted from a solution containing its parent cesium (137Cs). This barium isotope is commonly used in an undergraduate laboratory exercise for demonstrating the radioactive decay law. Undergraduate students using modest experimental equipment took the data pre-
sented in Figure $\mathrm{P} 44.62$ . Determine the half-life for the decay of $^{137} \mathrm{Ba}$ using their data.