1. In all living plants and animals, the ratio of the two isotopes of carbon, 14C (unstable, radioactive) and 12C (stable, non-radioactive), approaches that of the atmosphere, 1:31012. After plants or animals die, 14C decays to 14N (stable, non-radioactive) through a first-order nuclear reaction 14 6C ! 14 7N + e . In a fossil, the ratio of 14C to 12C is 1:3 1013, what is the age of this fossil? The half-life of 14C is 1 2 = 5730 years.

1. In all living plants and animals, the ratio of the two isotopes of carbon, 14C (unstable, radioactive) and 12C (stable, non-radioactive), approaches that of the atmosphere, 1.31012. After plants or animals die, 14C decays to 14N (stable, non-radioactive) through a first-order nuclear reaction 614C714N+e. In a fossil, the ratio of 14C to 12C is 1.31013, what is the age of this fossil? The half-life of 14C is 21=5730 years