|
|
|
||||
|
Neodymium - Nd General Information Discovery Neodymium was separated from the 'rare earth' didymia by Baron Auer von Welsbach in 1885 in Vienna, Austria. The other principal component of didymia was praseodymium, atomic number 59. Appearance Neodymium is a bright silvery-white metal. Source The principal sources of most lanthanides are the minerals monazite and bastnaesite. From these neodymium can extracted by ion exchange and solvent extraction techniques. The element can also be obtained by reducing the anhydrous chloride with calcium. Uses Neodymium is present in mischmetall up to 18%. This alloy is used in such products as cigarette lighters where a light flint operates. Neodymium is also a component, along with praseodymium, of didymia, a special glass used in goggles in glass blowing and welding. The element colours glass delicate shades of violet, wine-red and grey. It is used to make glass which transmits the tanning rays of the sun but not the harmful infrared rays. Biological Role Neodymium has no known biological role, is moderately toxic and a known eye irritant. General Information Neodymium reacts slowly with cold water and quickly with hot water. It quickly tarnishes in air and so is usually kept under paraffin or sealed in plastic. It exists in two allotropic forms, with a transformation from hexagonal to body-centred cubic taking place at 863K. |
| Physical Information | |||
| Atomic Number | 60 | ||
| Relative Atomic Mass (12C=12.000) | 144.24 | ||
| Melting Point/K | 1294 | ||
| Boiling Point/K | 3341 | ||
| Density/kg m-3 | 7007 (293K) | ||
| Ground State Electron Configuration | [Xe]4f46s2 | ||
| Electron Affinity(M-M-)/kJ mol-1 | -50 |
| Key Isotopes | ||||||
| nuclide | 142Nd | 143Nd | 144Nd | 145Nd | 146Nd | |
| atomic mass | 141.9 | 142.91 | 143.9 | 144.9 | 145.9 | |
| natural abundance | 27.16% | 12.18% | 23.80% | 8.29% | 17.19% | |
| half-life | stable | stable | stable | stable | stable | |
| nuclide | 147Nd | 148Nd | 150Nd | |||
| atomic mass | 147.9 | 149.9 | ||||
| natural abundance | 0% | 5.75% | 5.63% | |||
| half-life | 11 days | stable | stable | |||
| Other Information | ||
| Enthalpy of Fusion/kJ mol-1 | 7.11 | |
| Enthalpy of Vaporisation/kJ mol-1 | 328 | |
| Oxidation States | ||
| main | Nd+3 | |
| others | Nd+2, Nd+4 | |
| Ionisation Energies/kJ mol-1 | ||
| M - M+ | 529.6 | |
| M+ - M2+ | 1035 | |
| M2+ - M3+ | 2130 | |
| M3+ - M4+ | 3899 | |
| M4+ - M5+ | ||
| M5+ - M6+ | ||
| M6+ - M7+ | ||
| M7+ - M8+ | ||
| M8+ - M9+ | ||
| M9+ - M10+ | ||
|
|
|
|
|