11 I where A is the amount, in grams, of the isotope The decay of the radioactive isotope technetium99m is modeled by the equation A remaining after a given time, t, in hours, and P is the initial amount, in grams, of the isotope. If a scientist initially has 3 grams of technetium-99m, in approximately how many hours will she have only 1 gram of the isotope remaining? = Pe 0.1155t A) 0.1 hour B) 2.9 hours C) 26.0 hours D 9.5 hours