Which nuclide in each pair would you expect to have the longer half-life? a. Cs-149 or Cs-139

Video transcript

hey everyone we're asked to identify which isotope, a barium is expected to have a longer half life. We have Barium 1 34 and Barium 1 25. Looking at our periodic table, we find that barium has an atomic number of And because its atomic number is in between 40 and 80 than our n oversee ratio Must be equal to 1.50. And the closer we are to that value of 1.50, the more staple it will be and the longer the half life. So let's go ahead and calculate our anniversary ratios for both. For Barium 1 34 we're going to take our atomic mass of 1 and subtract our atomic number of Dividing all this by 56, we end up with a value of 1.39. Next for Barium 1 25 we're going to take our 1 25 and subtract 56 dividing everything by 56 we end up with a value of 1.23 and because at 1.39 is closer to that N oversee ratio of 1.50. Barium 1 34 is expected to have a longer half life than Barium 25. So I hope this made sense and let us know if you have any questions