Question

Carbon 14(c) dating assumes that the carbon dioxide on Earth today has the same radioactive content as it did centuries ago. If this is true, the amount of 14c absorbed by a tree that grew several centuries ago should be the same as the amount of absorbed by a tree growing today. A piece of ancient charcoal contains only 14% as much radioactive carbon as a plece of modern charcoal. How long ago was the tree burned to make the ancient charcoal given that the half-life of C is 5700 years? (Round your answer to the nearest whole number.)

Answer 1

here initial amount is

40 = 100% = 1

and present amount is

A= 14% = 0.14

half-life is p=5700 years

oln (0.5) = ln (0.14)

5700 ln (0.14) In (0.5)

t = 16168.057