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Neodymium

Praseodymium - Neodymium - Promethium
Nd
U  
 
 
General
Name, Symbol, NumberNeodymium, Nd, 60
Chemical series Lanthanides
Group, Period, Block_ [?], 6 , f
Density, Hardness 6800 kg/m3, no data
Appearance silvery white, yellowish tinge
Atomic properties
Atomic weight 144.24(3) amu
Atomic radius (calc.) 185 (206) pm
Covalent radius no data
van der Waals radius no data
Electron configuration [Xe]4f46s²
e- 's per energy level2, 8, 18, 22, 8, 2
Oxidation states (Oxide) 3 (mildly basic)
Crystal structure Hexagonal
Physical properties
State of matter solid (__)
Melting point 1297 K (1875 F)
Boiling point 3373 K (5612 F)
Molar volume 20.59 ×10-3 m3/mol
Heat of vaporization 273 kJ/mol
Heat of fusion 7.14 kJ/mol
Vapor pressure 6.03E-3 Pa at 2890 K
Velocity of sound 2330 m/s at 293.15 K
Miscellaneous
Electronegativity 1.14 (Pauling scale)
Specific heat capacity 190 J/(kg*K)
Electrical conductivity 1.57 106/m ohm
Thermal conductivity 16.5 W/(m*K)
1st ionization potential 533.1 kJ/mol
2nd ionization potential 1040 kJ/mol
3rd ionization potential 2130 kJ/mol
4th ionization potential 3900 kJ/mol
Most stable isotopes
isoNAhalf-life DMDE MeVDP
142Nd27.13142Nd is stable with 82 neutrons
143Nd12.18143Nd is stable with 83 neutrons
144Nd23.82.29E15 aα1.905140Ce
145Nd8.3145Nd is stable with 85 neutrons
146Nd17.19146Nd is stable with 86 neutrons
148Nd5.76148Nd is stable with 88 neutrons
150Nd5.641.1E19 aDouble β-3.367150Sm
SI units & STP are used except where noted.

Neodymium is a chemical element in the periodic table that has the symbol Nd and atomic number 60.

Table of contents

Notable characteristics

Neodymium, a rare earth metal, is present in misch metal to the extent of about 18%. The metal has a bright silvery metallic luster; however, being one of the more reactive rare-earth metals, Neodymium quickly tarnishes in air, forming an oxide that spalls off and exposes the metal to further oxidation.

Applications

Uses of Neodymium include:

History

Neodymium was discovered by Baron Carl F. Auer von Welsbach[?], an austrian chemist, in Vienna in 1885. He separated neodymium, as well as the element Praseodymium, from a material known as didymium[?]; however, it was not isolated in relatively pure form until 1925. The name Neodymium is derived from the greek words neos, new, and didymos, twin.

Today, Neodymium is primarily obtained from 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.

Biological role

Neodymium has no known biological role.

Occurrence

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 bastnosite ((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 from other rare earth elements.

Compounds

Neodymium compounds include:

Isotopes

Naturally occurring Neodymium 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 radioisotopes, 144-Nd and 150-Nd. 31 radioisotopes have been characterized, with the most stable being 150-Nd with a half-life of 1.1E19 years, 144-Nd with a half-life of 2.29E15 years, and 147-Nd with a half-life of 10.98 days. All of the remaining radioactive isotopes have half-lifes that are less than 3.38 days, and the majority of these have half lifes that are less than 71 seconds. This element also has 4 meta states with the most stable being 139m-Nd (t 5.5 hours), 135m-Nd (t 5.5 minutes) and 141m-Nd (t 62.0 seconds).

The primary decay mode before the most abundant stable isotope, 142-Nd, is electron capture and the primary mode after is beta minus decay. The primary decay products before 142-Nd are element Pr (Praseodymium) isotopes and the primary products after are element Pm (Lead) isotopes.

Precautions

All Neodymium compounds should be regarded as highly toxic. Furthermore, Neodymium compounds are skin and eye irritants, and the metal dust presents a fire and explosion hazard.

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