Tritium, a radioactive isotope of hydrogen, has a half-life of 12.4 years. Of an initial sample of 60 grams, how much will remain after 81 years?
A)2.8307 grams
B)0.6483 grams
C)15.0000 grams
D)53.9595 grams
E)0.0000 grams

Question

Quizplus · Accepted Answer

We can use the formula:
(amount remaining) = (initial amount) x (1/2)^(time elapsed/half-life)
Plugging in the values:
(amount remaining) = 60 x (1/2)^(81/12.4)
(amount remaining) = 0.6483 grams

Tritium, a Radioactive Isotope of Hydrogen, Has a Half-Life of 12.4