|Boiling Point: 3341°K, 3068°C, 5554°F
Melting Point:1289°K, 1016°C, 1861°F
Electrons Energy Level: 2,8,18,22,8,2
Isotopes: 33 + 5 Stable + 5 meta states
Heat of Vaporization: 273 kJ/mol
Heat of Fusion: 7.14 kJ/mol
Density: 7.01g/cm3 @ 300°K
Specific Heat: 0.19 J/gK
Atomic Radius: 2.64Å
Ionic Radius: 0.995Å
Electronegativity: 1.14 (Pauling); 1.07 (Allrod Rochow)
1s2 2s2p6 3s2p6d10 4s2p6d10f4 5s2p6 6s2
Neodymium, Greek neos + didymos (new twin). In 1841, Mosander, extracted from cerite a new rose-colored oxide, which he believed contained a new element. He named the element didymium, as it was an inseparable twin brother of lanthanum. In 1885 Baron Carl Auer von Welsbach, an Austrian chemist, separated didymium into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate by means of spectroscopic analysis.. While the free metal is in misch metal, long known and used as a pyrophoric alloy for light flints, the element was not isolated in relatively pure form until 1925.
Neodymium is frequently misspelled as neodynium. Today, neodymium is primarily obtained through an ion exchange process of monazite sand (Ce,La,Th,Nd,Y)PO4, a material rich in rare earth elements, and through electrolysis of its halide salts.
The silvery-white metal oxidizes easily in air and reacts with water, displacing hydrogen gas. Although another of the "rare" earth metals, neodymium is actually more abundant than many better known metals such as gold, silver, tin and lead. Neodymium quickly tarnishes in air. The tarnishing forms an oxide layer that falls off, which exposes the metal to further oxidation. Although a "rare earth metals," it constitutes 38 ppm of Earth's crust.
It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals. The element may be obtained by separating neodymium salts from other rare earths by ion-exchange or solvent extraction techniques, and by reducing anhydrous halides such as NdF3 with calcium metal. Other separation techniques are possible. Neodymium exists in two allotropic forms, with a transformation from a double hexagonal to a body-centered cubic structure taking place at 863oC.
Misch metal, used in lighter flints, is about 18% neodymium. The element is also used in the manufacture of artificial rubies for laser applications.
Neodymium is never found in nature as the free element; rather, it occurs in ores such as monazite sand (Ce,La,Th,Nd,Y)PO4 and bastnasite (Ce,La,Th,Nd,Y)(CO3)F that contain small amounts of all the rare earth metals. Neodymium can also be found in Misch metal; it is difficult to separate it from other rare earth elements.
Neodymium makes up about 18% of Misch metal, a material that is used to make flints for lighters. Neodymium is also a component of didymium glass, which is used to make certain types of welder's and glass blower's goggles. Neodymium is added to glass to remove the green color caused by iron contaminants. It can also be added to glass to create violet, red or gray colors. Some types of glass containing neodymium are used by astronomers to calibrate devices called spectrometers and other types are used to create artificial rubies for lasers. Some neodymium salts are used to color enamels and glazes.
Neodymium compounds include
Naturally occurring Neodymium is composed of 5 stable isotopes, 142Nd, 143Nd, 145Nd, 146Nd and 148Nd, with 142Nd being the most abundant (27.2% natural abundance), and 2 radioisotopes, 144Nd and 150Nd. In all, 31 radioisotopes of Neodymium have been characterized, with the most stable being 150Nd with a half-life (T½) of >1.1×1019 years, 144Nd with a half-life of 2.29×1015 years, and 147Nd with a half-life of 10.98 days. All of the remaining radioactive isotopes have half-lives that are less than 3.38 days, and the majority of these have half-lives that are less than 71 seconds. This element also has 4 meta states with the most stable being 139Ndm (T½ 5.5 hours), 135Ndm (T½ 5.5 minutes) and 141Ndm (T½ 62.0 seconds).
The primary decay mode before the most abundant stable isotope, 142Nd, is electron capture and the primary mode after is beta minus decay. The primary decay products before 142Nd are element Pr (praseodymium) isotopes and the primary products after are element Pm (promethium) isotopes.
|144Nd||143.9100873||2.29 x 1015 years|
|150Nd||149.920891||6.7 x1018 years|
|Neodymium has a low-to-moderate acute toxic rating; however its toxicity has not been thoroughly investigated. As with other rare earths, neodymium should be handled with care. The metal should be kept under light mineral oil or sealed in a plastic material.|
Neodymium dust and salts are very irritating to the eyes and mucous membranes, and moderately irritating to skin. Breathing the dust can cause lung embolisms, and accumulated exposure damages the liver.
|Neodymium metal dust is a combustion and explosion hazard. Neodymium also acts as an anticoagulent, especially when given intravenously.|
Neodymium magnets have been tested for medical uses such as magnetic braces and bone repair, but biocompatibility issues have prevented widespread application.
Atomic Radius (Å): 2.64Å
Electrochemical Equivalents: 1.7939g/amp-hr
Atomic Mass Average: 144.24