Erbium metals lutetium neodymium

B. Evans, Assistant Chemist. Rare-Earth Information Center. Energy itnd Mineral Resources Research Institute. Iowa Slate University. Ames. I,A. http //www.cxternal.ameslab.gov/. Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Lutetium Neodymium Rare-Earth Elements and Metals Praseodymium Samarium Scandium Terbium Thulium Ytterbium and Yttrium Daniel F. Farkas, Oregon State University. Corvallis. OR. http // oregonstate.edu/. Food Processing... 

It surprises most people to learn that several of the so-called rare earth elements are not actually that rare compared to much more familiar elements. Neodymium, praseodymium, samarium, gadolinium, dysprosium, erbium, and ytterbium are all more abundant than more familiar elements like bromine, uranium, or tin. Europium, holmium, terbium, lutetium, and thulium are more abundant than iodine, silver, or mercury. Yet few people have even heard of most of the rare earths. The reason is that rare earths tend not to concentrate in large ore deposits in the way that better known metals do. Historically there have been fewer profits to be made from mining rare earth elements, and there have been fewer applications developed for them in industry. 

Cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu) are called lanthanoid series. Lanthanum (La) which is a /-block element is also considered to be a lanthanoid. Therefore, the lanthanoid series comprises the fifteen elements with atomic numbers 57 (La) through 71 (Lu). Lanthanoids are grouped because of their chemical similarities and their properties only differ slightly with atomic number. All lanthanoids are relatively soft and reactive metals. Rare earth metals are a collection of seventeen chemical elements in the periodic table, namely. Sc, Y and the fifteen lanthanoids. Sc and Y are considered to be rare earths since they tend to occur in the same ore deposits as the lanthanoids and exhibit similar chemical properties. Table 2.86 summarizes some physical properties of a number of lanthanoids. 

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