Topics: Sciencetech | Mail Online
Carbon-14 is a radioisotope of Carbon. It is produced in the Earth’s upper atmosphere when Nitrogen-14 is broken down to form the unstable Carbon-14 by the action of cosmic rays. The unstable Carbon-14 is transported down to the lower atmosphere by atmospheric activity such as storms.
The half life for Carbon-14 is 5730 years. Therefore half of the Carbon-14 has decayed after 5730 years. Half of the remaining Carbon-14 then decays over the next 5730 years leaving one fourth of the original amount. By measuring the ratio of Carbon-14 in a sample and comparing it to the amount in a recently deceased sample its date can be determined.