Question

Americium-241 is a radioactive substance used in smoke detectors. The half life of americium is 432 years. If a smoke detector initially contains 1 gram of Americium 241, how much will remain in 1,296 years?(1 point)
Responses

0.125 g
0.125 g

0.25 g
0.25 g

0.5 g
0.5 g

1.0 g

Answer 1

Half-life 432 years → after 1296 years that's 1296/432 = 3 half-lives. Amount = 1*(1/2)^3 = 1/8 = 0.125 g.