The half-life of carbon-14 is 5,600 years.A fossil that has one-eighth the normal proportion of carbon-14 to carbon-12 is probably
A)2,800 years old.
B)5,600 years old.
C)11,200 years old.
D)16,800 years olD.
E)22,400 years old.

Question

Quizplus · Accepted Answer

The fossil has one-eighth the normal proportion of carbon-14, which means it has gone through three half-lives (since 1/2^3 = 1/8). Each half-life is 5,600 years, so 3 half-lives is 16,800 years.

The Half-Life of Carbon-14 Is 5,600 Years