The half-life of carbon-14 is about 5,730 years. A fossil that has 1/16 of the normal proportion of carbon-14 to carbon-12 should be about how many years old?
A) 2,800
B) 11,200
C) 16,800
D) 22,900

Question

Quizplus · Accepted Answer

The fossil has 1/16 of the original carbon-14, which means it has gone through 4 half-lives (since 1/2^4 = 1/16). Each half-life is 5,730 years, so 4 half-lives is 4 * 5,730 = 22,920 years, which is approximately 22,900 years.

The Half-Life of Carbon-14 Is About 5,730 Years