Abstract
This paper examines how both carbon-14 and uranium-238 are used to date fossils and how both methods are based on measuring the decay that has occurred in these elements. It looks at how carbon-14 dating is used for organic material, plants and animals, while uranium-238 is used primarily for geographic formations. It also discusses how both methods of dating are subject to potential sample contamination and, therefore, inaccurate readings; the addition of foreign material in both types of samples can provide either younger or older results, dependent on the material.

From the Paper
"Radioactive elements decay at unique rates, dependant on the isotope. This rate of decay is known as half-lives, it is the time necessary for of the atoms to decay in a particular element. The decay follows a geometric scale, in that in the first half-life of an element, of the atoms decay, yet in the second half-life, of those remaining decay, meaning a of the original atoms decay, and so forth. By measuring this decay, and knowing the half life of an element, scientists can date a sample."

Tags:isotope, atoms, half, life, decay, chronometric