Compare the two methods of dating fossils
For most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant.
It is not affected by external factors such as temperature, pressure, chemical environment, or presence of a magnetic or electric field.
For instance, carbon-14 has a half-life of 5,730 years.
After an organism has been dead for 60,000 years, so little carbon-14 is left that accurate dating cannot be established.
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 undergo radioactive decay and spontaneously transform into a different nuclide.
Alternatively, if several different minerals can be dated from the same sample and are assumed to be formed by the same event and were in equilibrium with the reservoir when they formed, they should form an isochron. In uranium–lead dating, the concordia diagram is used which also decreases the problem of nuclide loss.Radiometric dating is also used to date archaeological materials, including ancient artifacts.Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter.Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e.g., tritium) to over 100 billion years (e.g., samarium-147).
The procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate.