Answer Happy

Substance gallium-67 cobalt-60 technetium-99m americium-241 carbon-14 uranium-235 Use nuclear medicine manufacturing nuclear medicine construction archeological dating atomic power Half-life 80 hours 5.3 years 6 hours 432 years 5,715 years 703,800,000 years The formula for radioactive decay: In() A(t) = Age ((s) where A, is the amount initially present T is the half-life of the substance t is the time period over which the substance is studied A(t) is the amount of the substance present after timet Using the above table and formula, solve the following: How long will it take for 35% of a 800-gram sample of americium-241 to decay? It will take years Round your answer to 2 decimal places. Hint: If 35% has decayed, what percentage is remaining?