Radioactive elements are unstable; they breakdown spontaneously into more stable atoms over time, a process known as radioactive decay.Radioactive decay occurs at a constant rate, specific to each radioactive isotope.It may be used to date a wide range of natural and man-made materials.
These are often characterised as the norm, rather than the exception.
I thought it would be useful to present an example where the geology is simple, and unsurprisingly, the method does work well, to show the quality of data that would have to be invalidated before a major revision of the geologic time scale could be accepted by conventional scientists.
The example used here contrasts sharply with the way conventional scientific dating methods are characterized by some critics (for example, refer to discussion in "Common Creationist Criticisms of Mainstream Dating Methods" in the Age of the Earth FAQ and Isochron Dating FAQ).
A common form of criticism is to cite geologically complicated situations where the application of radiometric dating is very challenging.
Radiometric dating is also used to date archaeological materials, including ancient artifacts.
Radiometric dating methods are used to establish the geological time scale.Since the 1950s, geologists have used radioactive elements as natural "clocks" for determining numerical ages of certain types of rocks. "Forms" means the moment an igneous rock solidifies from magma, a sedimentary rock layer is deposited, or a rock heated by metamorphism cools off.It's this resetting process that gives us the ability to date rocks that formed at different times in earth history.Radiometric dating (often called radioactive dating) is a way to find out how old something is.The method compares the amount of a naturally occurring radioactive isotope and its decay products, in samples. It is the main way to learn the age of rocks and other geological features, including the age of the Earth itself.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 change into a different nuclide by radioactive decay.