What is the half-lifeof 100.0g sample of nitrogen-16 that decays to 12.5 g of nitrogen-16 in 21.6 s?

Answer 1

The half-life is the time it takes for half of a radioactive sample to decay. In this case, the sample of nitrogen-16 decays from 100.0 g to 12.5 g, which involves three half-lives (100 g to 50 g, 50 g to 25 g, and 25 g to 12.5 g). Since this decay occurs over 21.6 seconds, we can calculate the half-life by dividing the total time by the number of half-lives: 21.6 s / 3 = 7.2 s. Therefore, the half-life of nitrogen-16 is 7.2 seconds.