Start studying relative dating: Lesson for Kids Creative Process: Because of its short half-life, the number of C isotopes in a sample is negligible after about 50, years, making it impossible to use for dating older samples. Carbon combines with oxygen to create carbon dioxide. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. Try refreshing the page, or contact customer support. By anyone's standards, 50 billion years is a long time.
The uranium content of the sample has to be known, but that can be determined by placing a plastic film over the polished slice of the material, and bombarding it with slow neutrons.
Introduction to Physical Geology: Become a Member Already a member? A particular isotope of a particular element is called a nuclide. Well, a simple explanation is that it is the time required for a quantity to fall to half of its starting value. This can be seen in the concordia diagram, where the samples plot along an errorchron straight line which intersects the concordia curve at the age of the sample.