A 300,000-gallon tank has been storing aqueous radioactive waste since approximately 1945. The primary radioactive species in this waste is cesium, which is present as both radioactive and non-radioactive isotopes. The total cesium concentration is 0.005 g Cs/L and half of the Cs is the radioactive isotope cesium-137 (137Cs). It also is known that the specific radioactivity of 137Cs is 86.58 Ci/g, where Ci represents the unit curie, which is defined as 3.7 ? 1010 radioactive decays per s. In the radioactive decay of 137Cs, cesium is converted to barium at a rate that satisfies the expression Where N and N0 are amounts of cesium and t0.5 is the half-life of the isotope, which for 137Cs is 30.1 years. (a) What fraction of the cesium would have to be removed from the solution in order for the radioactivity to be reduced to 0.001 Ci/L? (b) What would be the total amount of Cs removed from the tank in order to reach that level of radioactivity? (c) Assuming the radioactive cesium was placed in the tank in 1945, what was the original total concentration of cesium and the corresponding radioactivity in Ci/L?