12:1

The half-life of plutonium-241 is approximately 13 years. (a) How much of a sample weighing 2 g will remain after 70 years? (b) How much time is necessary for a sample weighing 2 g to decay to 0.1 g? (a) After 70 years, g will remain. (Do not round until the final answer. Then round to four decimal places as needed.) (b) The sample will decay to 0.1 g after years. (Do not round until the final answer. Then round to the nearest year.)