Atomic dating using isotopes
An atom with the same number of protons in the nucleus but a different number of neutrons is called an isotope.
For example, uranium-238 is an isotope of uranium-235, because it has 3 more neutrons in the nucleus.
Radiometric dating is a means of determining the "age" of a mineral specimen by determining the relative amounts present of certain radioactive elements.
By "age" we mean the elapsed time from when the mineral specimen was formed.
The number of protons in the nucleus of an atom is called its atomic number.(Creationists claim that argon escape renders age determinations invalid.However, any escaping argon gas would lead to a determined age younger, not older, than actual.Countries that want to have their own nuclear fuel manufacturing capabilities argue that they need enrichment plants, but opponents argue that they are just looking to produce nuclear weapons. When one speaks of isotopes, they are referring to the set of nuclides that have the same number of protons.Nuclide is a more general term, referring to a nuclear species that may or may not be isotopes of a single element.