After four half-lives have elapsed, what fraction of the original amount has changed into another element?

Question

Quizplus · Accepted Answer

Each half-life represents a reduction in the original amount by half. After four half-lives, the original amount is reduced by a factor of 2^4 = 16. Therefore, only 1/16 of the original amount remains, while 15/16 of it has changed into another element. So the fraction changed is 15/16.

After Four Half-Lives Have Elapsed, What Fraction of the Original