How are carbon isotopes useful ?

Carbon Isotopes (such as C-12 and C-14) can be used in the process of radiometric dating. Carbon is specifically used for dating organic material (things that were once alive). This is presented through the use of a half-life (the amount of time it takes half of the carbon atoms to decay.) Carbon has a half-life of 5730 years, this means it takes 5730 years for half of the number of atoms in the sample to decay. The sample must be older than one half-life of carbon but younger than (about) 50,000 years.