The half-life of carbon-14 is about 5,730 years.If an ancient cave painting was found to have about 25% of the carbon-14 of a now-living object,about how old is the cave painting?

Question

Quizplus · Accepted Answer

The cave painting is about 11,500 years old. This is because one half-life (5,730 years) would reduce the carbon-14 to 50%, and two half-lives would reduce it to 25%, which matches the given condition.

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