How long would it take for all but of a sample of 90-Sr to decay, if the half-life of 90-5r is years? Give your answer in years. 0.01% 28.8 Problem 9. (Chernobyl Disaster) After the sudden release of radioactivity from the Chernobyl nuclear reactor accident in 1986, the radioactivity of milk in Poland rose to due to iodine-131 present in the grass eaten by dairy cattle. Radioactive iodine, with a half-life is particularly hazardous because the thyroid gland concentrates iodine. 2000 Bq/L 8.0 days A. What is the time constant that characterizes the decay of ""| if it has a half-life of ? Give your answer in units of days a? 8 days B. What is the storage time, in days, needed to decrease the ""| content of cheese produced from these cows milk to of the original level? 15%