Topics: Science - edu.ajlc.waterloo.on.ca
In the 1950s W.F. Libby and others (University of Chicago) devised a method of estimating the age of organic material based on the decay rate of carbon-14. Carbon-14 dating can be used on objects ranging from a few hundred years old to 50,000 years old.
Free carbon, including the carbon-14 produced in this reaction, can react to form carbon dioxide, a component of air.
However, when a plant or animal dies, it stops taking in carbon as food or air. The radioactive decay of the carbon that is already present starts to change the ratio of 14 C/ 12 C. By measuring how much the ratio is lowered, it is possible to make an estimate of how much time has passed since the plant or animal lived. The decay of carbon-14 is: