For inorganic matter and for older materials, isotopes of other elements, such as potassium, uranium, and strontium, are used.
Mikhail Marov of the Vernadsky Institute of Geochemistry and Analytical Chemistry said scientists had determined the meteorite's age by observing the amount of radioactive isotopes and their decay byproducts, a technique called of a granodiorite at the Cuttaburra A prospect indicates that this mineralised system may be Middle Silurian in age and thus indicating that the host rocks are older than those hosting the Cobar-type deposits.
For example, in the The decay constant has dimensions of reciprocal seconds.
In the special case in which parent and daughter atoms are present in equal quantities, the age of the specimen is the half-life of the parent isotope: The first assumption, that the amount of the daughter isotope in the original rock is known, is the weakest assumption.
Radiocarbon dating is one kind of radiometric dating, used for determining the age of organic remains that are less than 50,000 years old.Additionally, elements may exist in different isotopes, with each isotope of an element differing in the number of neutrons in the nucleus.A particular isotope of a particular element is called a nuclide. That is, at some point in time, an atom of such a nuclide will spontaneously transform into a different nuclide.Many radioactive substances decay from one nuclide into a final, stable decay product (or "daughter") through a series of steps known as a decay chain.In this case, the half-life is usually given is for the entire chain, rather than just one step in the chain.