(Solved): Radioactive isotopes (radioisotopes) are extremely important for some medical tests and procedures. ...

Radioactive isotopes (radioisotopes) are extremely important for some medical tests and procedures. A common radioisotope used for medical imaging is technetium- 99 . Technetium- 99 is used because it releases $140\mathrm{keV}$ gamma rays that are easily detected outside of the body and doesn't damage surrounding tissue. It has a short half-life and the human body easily excretes its daughter products. The short half-life that makes it safe also means that the hospital needs a constant supply. To solve this problem, scientists developed a technetium- 99 generator from molybdenum- 99 , a byproduct of spent nuclear reactor fuel. The molybdenum- 99 needs replacing weekly instead of daily shipments of technetium- 99 . The generator starts with molybdenum- 99 , which decays into technetium99 , which can be separated by a relatively easy chemical process. As a learning exercise, a medical student is asked to monitor the decay of a molybdenum- 99 sample of $100\mathrm{g}$ over a week. The student measures the following values. Graph the information. What is the half-life of molybdenum? Explain how you determined the half-life. What is the decay equation for molybdenum-99 into technetium-99? The decay of technetium- 99 releases a 140 keV gamma ray. How much mass is changed into energy to create the gamma ray?