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Neodymium is the fourth member of the lanthanide series. In the periodic table, it appears between the lanthanides praseodymium to its left and the radioactive element promethium to its right, and above the actinide uranium. Its 60 electrons are arranged in the configuration [Xe]4f 4 6s 2, of which the six 4f and 6s electrons are valence.
The rare-earth elements (REE), also called the rare-earth metals or rare earths or, in context, rare-earth oxides, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals.
Radioactive isotope table "lists ALL radioactive nuclei with a half-life greater than 1000 years", incorporated in the list above. The NUBASE2020 evaluation of nuclear physics properties F.G. Kondev et al. 2021 Chinese Phys. C 45 030001. The PDF of this article lists the half-lives of all known radioactives nuclides.
edit. Naturally occurring neodymium (60 Nd) is composed of 5 stable isotopes, 142 Nd, 143 Nd, 145 Nd, 146 Nd and 148 Nd, with 142 Nd being the most abundant (27.2% natural abundance), and 2 long-lived radioisotopes, 144 Nd and 150 Nd. In all, 33 radioisotopes of neodymium have been characterized up to now, with the most stable being naturally ...
Natural radioactive elements are present in very low concentrations in Earth's crust, and are brought to the surface through human activities such as oil and gas exploration or mining, and through natural processes like leakage of radon gas to the atmosphere or through dissolution in ground water. Another example of TENORM is coal ash produced ...
Radiometric dating. Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to ...
Inventor Masato Sagawa demonstrating a NdFeB magnet's force with 2 kg bottle. A neodymium magnet (also known as NdFeB, NIB or Neo magnet) is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd 2 Fe 14 B tetragonal crystalline structure. [1] They are the most widely used type of rare-earth magnet.
Samarium has seven naturally occurring isotopes, and neodymium has seven. The two elements are joined in a parent–daughter relationship by the alpha decay of parent 147 Sm to radiogenic daughter 143 Nd with a half-life of 1.06 × 10 11 years and by the alpha decay of 146 Sm (an almost-extinct radionuclide with a half-life of 1.03(5) × 10 8 years [a]) to produce 142 Nd.