4.) Consider the A = 218 isobar. There are no stable nuclides along this isobar, but let's pretend that a decay is impossible. a.) (6 points) Using the semi-empirical mass formula as described in Cottingham & Greenwood, find the -stable nuclide on the A = 218 isobar. b.) (8 points) Let Z be the atomic number of the -stable nuclide found in part (a). Using the semi-empirical mass formula, find the masses of the -stable nuclide and its neighbors at Z, -2, Z 1, Z + 1, and Z + 2 (always along the A = 218 isobar). Even though the parameters of the semi-empirical mass formula are only given with a few significant figures, you should consider them to be exact for these calculations. Write your answer to a precision of 1 keV, 1 u or better. c.) (8 points) By calculating the appropriate Q values, predict the primary weak decay mode (still ignoring a decay) for each of the neighboring nuclides from part (b). Use the masses calculated in part (b). d.) (8 points) By calculating the appropriate Q values, predict the primary weak decay mode (still ignoring a decay) for each of the neighboring nuclides from part (b). This time, use the measured masses from the IAEA table. e.) (5 points) Comment on the similarities and differences between your predicted decays modes from parts (c) and (d). Note: Since this problem requires doing multiple similar calculations, you may want to create a spreadsheet or write some code to do this problem. Putting all of these calculations into a calculator individually is probably a recipe for mistakes.