Lanthanides Rare earth elements

RBS REE Rutherford backscattering spectroscopy Rare earth elements (lanthanides + Y)... 

Despite their name, rare earth elements , lanthanides are in fact not especially rare each is more common in the earth s crust than silver, gold or platinum. They possess characteristic 4/ open-shell configurations and exhibit... 

NOTE Rare earth elements (lanthanides) are designated by the common S3onbol Ln (except in special cases where R.E. has been used). Thus, for their compoimds see under Ln. 

Sadolinium Element symbol, Gd rare earth element/lanthanide Z 64 A(r)... 

Geology, Geochemistry, and Natural Abundances of the Rare Earth Elements Lanthanides Coordination Chemistry Lanthanide Alkoxides. 

Why do rare-earth elements (lanthanides) have similar chemical properties and sharp spectral lines even when incorporated in a crystal matrix ... 

Therald became an internationally recognized authority on the chemistry of the rare earth elements (lanthanides) and published 94 research papers and books in this area alone. During his 45 years of teaching and research, he guided the laboratory research of 43 Ph.D. students, 20 postdoctoral fellows, and 11 M.S. and 25 B.S. students for a total of 99 research students in inorganic chemistry. Of these, at least 39 became professors themselves at universities in the United States, Taiwan, Spain, India, Japan, Brazil, England, and Finland. Several became Department Chairs and one a College President. 

Elements in the s and p blocks of the table are referred to as typical elements whilst those in the d block are called transition elements and those in the/block are called actinides and lanthanides (or rare earth elements). 

Lanthanides is the name given collectively to the fifteen elements, also called the elements, ranging from lanthanum. La, atomic number 57, to lutetium, Lu, atomic number 71. The rare earths comprise lanthanides, yttrium, Y, atomic number 39, and scandium. Sc, atomic number 21. The most abundant member of the rare earths is cerium, Ce, atomic number 58 (see Ceriumand cerium compounds). 

In the sequence of structures from the large to the small rare-earth elements, the lanthanide contraction is manifested as shown in Figs. 19a and 19b. Within a structure, the cell volume diminishes linearly with the atomic number. If a certain, limiting value is reached, there is... 

The rare earth elements (R) are those from atomic numbers 57-71, emanating as a particular series from the parent element lanthanum (atomic no. 57). The set of 14 elements from cerium (58) through lutetium (71) inclusive are commonly known as the lanthanoid (or lanthanide Ln) series. The rare earths form a bridge at the... 

Krebs, Robert E. The history and use of our earth s chemical elements a reference guide. Westport (CT) Greenwood P, 1998. ix, 346p. ISBN 0-313-30123-9 A short history of chemistry — Atomic structure The periodic table of the chemical elements — Alkali metals and alkali earth metals - Transition elements metals to nonmetals — Metallics and metalloids - Metalloids and nonmetals — Halogens and noble gases - Lanthanide series (rare-earth elements) — Actinide, transuranic, and transactinide series... 

Several methods have been used to separate the lanthanides chemically solvent extraction, ion exchange chromatography, HPLC using Q-hydroxyisobutyric acid and, in limited cases, selective reduction of a particular metal cation.40-43 The use of di(2-ethylhexyl)orthophosphoric acid (HDEHP) for the separation of various rare-earth elements via solvent extraction has also been reported.44 16 This separation method is based on the strong tendency of Ln3+ ions to form complexes with various anions (i.e., Cl- or N03 ) and their wide range of affinities for com-plexation to dialkyl orthophosphoric acid. When the HDEHP is attached to a solid phase resin, the lanthanides can be selected with various concentrations of acid in order of size, with the smallest ion being the most highly retained. 

Rare earth elements are the general term for 15 kinds of lanthanide elements (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Py, Ho, Er, Tm, Yb, Lu) together with Sc and Y elements. They prefer trivalent states in the complex formation, though three elements (Eu, Sm, Yb) can assume tri- and divalent stateos and Ce a tri- or tetravalent state. Their ionic radii are fairly large (1.0-1.17 A) and their electronegativities are low (1.1-1.2). In fact, the former are much larger than those of... 

The rare earth elements (REE) are the lanthanides (defined as those elements with valence electrons in 4/orbitals), La, Ce, Pr, Nd, (Pm), Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. Often included for analysis, because they behave in a chemically similar way, although strictly not REE, are the Group 3 transition metals Y and Lu. The radioactive lanthanide element promethium (Pm) is excluded from analysis, since it is not found in samples because of its short half-life. 

Schumm, R. H. Wagman, D. D. Bailey, S. Evans, W. H. Parker, V. B. "Selected Values of Thermodynamic Properties. Table for the Lanthanide (Rare Earth) Elements (Elements 62 through 76 in the Standard Order of Arrangement)" Nat. Bur. Stand. Tech. Note No. 270-7, April 1973. 

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