For an isotope with a half-life of one day, at the end of three days the amount that remains is
A)none.
B)one-half.
C)one-quarter.
D)one-eighth.
E)none of the above

Question

Quizplus · Accepted Answer

After one day, half of the initial amount will remain. After two days, another half of the remaining amount will decay. So, at the end of two days, 1/4th of the initial amount will remain. After three days, another half of the remaining amount will decay. So, at the end of three days, only 1/8th of the initial amount will remain. Therefore, the answer is D) one-eighth.

For an Isotope with a Half-Life of One Day, at the End