Radiometric dating, often called radioactive dating, is a technique used to determine the age of materials such as rocks. It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. It is the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself, and it can be used to date a wide range of natural and man-made materials.
The best-known radiometric dating techniques include radiocarbon dating, potassium-argon dating, and uranium-lead dating. By establishing geological timescales, radiometric dating provides a ificant source of information about the ages of fossils and rates of evolutionary change, and it is also used to date archaeological materials, including ancient artifacts.
Dating using radioactive decay
The different methods of radiometric dating are accurate over different timescales, and they are useful for different materials. In many cases, the daughter nuclide is radioactive, resulting in a decay chain. This chain eventually ends with the formation of a stable, nonradioactive daughter nuclide.
Each step in such a chain is characterized by a distinct half-life. In these cases, the half-life of interest in radiometric dating is usually the longest one in the chain. This half-life will be the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter s.
Everything worth knowing about scientific dating methods
Systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years e. However, in general, the half-life of a nuclide depends solely on its nuclear properties and is essentially a constant.
Therefore, in any material containing a radioactive nuclide, the proportion of the original nuclide to its decay products changes in a predictable way as the original nuclide decays over time. This predictability allows the relative abundances of related nuclides to be used as a clock to measure the time it takes for the parent atom to decay into the daughter atom s.
A g sample of Cs is allowed to decay.
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Calculate the mass of Cs that will be left after 90 years. The half-life of Cs is 30 years. Third half-life 90 years total : The remaining 25 grams of Cs decay and Boundless vets and curates high-quality, openly d content from around the Internet.
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Radiocarbon helps date ancient objects—but it's not perfect
Nuclear Chemistry. Search for:. Dating Using Radioactive Decay.
Learning Objective Calculate the age of a radioactive sample based on the half-life of a radioactive constituent. Key Points The best-known techniques for radioactive dating are radiocarbon dating, potassium-argon dating and uranium-lead dating.
In any material containing a radioactive nuclide, the proportion of the original nuclide to its decay products changes in a predictable way as the original nuclide decays over time. Show Sources Boundless vets and curates high-quality, openly d content from around the Internet.
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