Fluorine absorption Nitrogen dating Obsidian hydration Seriation Stratigraphy. Additionally, elements may exist in different isotopes , with each isotope of an element differing in the number of neutrons in the nucleus. Earth sciences portal Geophysics portal Physics portal.
Samples are exposed to neutrons in a nuclear reactor. All ordinary matter is made up of combinations of chemical elements , each with its own atomic number , indicating the number of protons in the atomic nucleus. The possible confounding effects of contamination of parent and daughter isotopes have to be considered, as do the effects of any loss or gain of such isotopes since the sample was created. This is based on the beta decay of rubidium to strontium , with a half-life of 50 billion years. About the authors B.