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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.
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 ...
Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only 222 Rn has a sufficiently long half-life (3.825 days) for it to be released from the soil and rock where it is generated.
Samarskite and similar minerals contain lanthanides in association with the elements such as tantalum, niobium, hafnium, zirconium, vanadium, and titanium, from group 4 and group 5, often in similar oxidation states. Monazite is a phosphate of numerous group 3 + lanthanide + actinide metals and mined especially for the thorium content and ...
Unstable isotopes decay through various radioactive decay pathways, most commonly alpha decay, beta decay, or electron capture. Many rare types of decay, such as spontaneous fission or cluster decay, are known. (See Radioactive decay for details.) [citation needed] Of the first 82 elements in the periodic table, 80 have isotopes considered to ...
Promethium is a chemical element with symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in the Earth's crust at any given time. Promethium is one of the only two radioactive elements that are followed in the periodic table by elements with stable forms ...
This page discusses each of the main elements in the mixture of fission products produced by nuclear fission of the common nuclear fuels uranium and plutonium. The isotopes are listed by element, in order by atomic number. Neutron capture by the nuclear fuel in nuclear reactors and atomic bombs also produces actinides and transuranium elements ...
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.