Advertisement

Neodymium

From Academic Kids

PraseodymiumNeodymiumPromethium
Nd
U  
 
 
Missing image
Nd-TableImage.png
Image:Nd-TableImage.png

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
Missing image
Nd,60.jpg


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 ×10-6 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 yα1.905140Ce
145Nd8.3145Nd is stable with 85 neutrons
146Nd17.19146Nd is stable with 86 neutrons
148Nd5.76148Nd is stable with 88 neutrons
150Nd5.641.1E19 yβ-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.

Chemistry Clipart .Clipart provided by Classroom Clip Art (http://classroomclipart.com)
Enlarge
Chemistry Clipart .Clipart provided by Classroom Clip Art (http://classroomclipart.com)
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:

  • Neodymium is a component of didymium used for colouring glass to make welder's goggles.
  • Neodymium colours glass in delicate shades ranging from pure violet through wine-red and warm gray. Light transmitted through such glass shows unusually sharp absorption bands; the glass is used in astronomical work to produce sharp bands by which spectral lines may be calibrated. Neodymium is also used to remove the green colour caused by iron contaminants from glass.
  • Certain transparent materials with a small concentration of neodymium ions can be used in lasers for infrared wavelengths (1054-1064 nm), e.g. Nd:YAG (yttrium aluminium garnet), Nd:YLF (yttrium lithium fluoride), Nd:YVO4 (yttrium orthvanadate), Nd:glass.
  • Neodymium salts are used as a colourant for enamels.
  • Neodymium is used in very powerful permanent magnets - Nd2Fe14B. These magnets are cheaper and also stronger than samarium-cobalt magnets. Neodymium magnets appear in products such as Sennheiser or iPod in-ear headphones.
  • Neodymium ions are used in active laser media.
  • Probably because of similarities to Ca2+, Nd3+ has been reported [1] (http://www.regional.org.au/au/gcirc/2/399.htm) to promote plant growth. Rare earth element compounds are frequently used in China as fertilizer.

History

Neodymium was discovered by Baron Carl 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 by means of spectroscopic analysis; 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 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.

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 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.

Compounds

Neodymium compounds include:

Isotopes

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 (T?) 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 (T? 5.5 hours), 135Ndm (T? 5.5 minutes) and 141Ndm (T? 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.

Precautions

Neodymium metal dust is a combustion and explosion hazard.

Neodymium compounds, like all rare earth metals, are of low to moderate toxicity; however its toxicity has not been thoroughly investigated. 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 also acts as an anticoagulant, 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.

References

External links

Navigation

Academic Kids Menu

  • Art and Cultures
    • Art (http://www.academickids.com/encyclopedia/index.php/Art)
    • Architecture (http://www.academickids.com/encyclopedia/index.php/Architecture)
    • Cultures (http://www.academickids.com/encyclopedia/index.php/Cultures)
    • Music (http://www.academickids.com/encyclopedia/index.php/Music)
    • Musical Instruments (http://academickids.com/encyclopedia/index.php/List_of_musical_instruments)
  • Biographies (http://www.academickids.com/encyclopedia/index.php/Biographies)
  • Clipart (http://www.academickids.com/encyclopedia/index.php/Clipart)
  • Geography (http://www.academickids.com/encyclopedia/index.php/Geography)
    • Countries of the World (http://www.academickids.com/encyclopedia/index.php/Countries)
    • Maps (http://www.academickids.com/encyclopedia/index.php/Maps)
    • Flags (http://www.academickids.com/encyclopedia/index.php/Flags)
    • Continents (http://www.academickids.com/encyclopedia/index.php/Continents)
  • History (http://www.academickids.com/encyclopedia/index.php/History)
    • Ancient Civilizations (http://www.academickids.com/encyclopedia/index.php/Ancient_Civilizations)
    • Industrial Revolution (http://www.academickids.com/encyclopedia/index.php/Industrial_Revolution)
    • Middle Ages (http://www.academickids.com/encyclopedia/index.php/Middle_Ages)
    • Prehistory (http://www.academickids.com/encyclopedia/index.php/Prehistory)
    • Renaissance (http://www.academickids.com/encyclopedia/index.php/Renaissance)
    • Timelines (http://www.academickids.com/encyclopedia/index.php/Timelines)
    • United States (http://www.academickids.com/encyclopedia/index.php/United_States)
    • Wars (http://www.academickids.com/encyclopedia/index.php/Wars)
    • World History (http://www.academickids.com/encyclopedia/index.php/History_of_the_world)
  • Human Body (http://www.academickids.com/encyclopedia/index.php/Human_Body)
  • Mathematics (http://www.academickids.com/encyclopedia/index.php/Mathematics)
  • Reference (http://www.academickids.com/encyclopedia/index.php/Reference)
  • Science (http://www.academickids.com/encyclopedia/index.php/Science)
    • Animals (http://www.academickids.com/encyclopedia/index.php/Animals)
    • Aviation (http://www.academickids.com/encyclopedia/index.php/Aviation)
    • Dinosaurs (http://www.academickids.com/encyclopedia/index.php/Dinosaurs)
    • Earth (http://www.academickids.com/encyclopedia/index.php/Earth)
    • Inventions (http://www.academickids.com/encyclopedia/index.php/Inventions)
    • Physical Science (http://www.academickids.com/encyclopedia/index.php/Physical_Science)
    • Plants (http://www.academickids.com/encyclopedia/index.php/Plants)
    • Scientists (http://www.academickids.com/encyclopedia/index.php/Scientists)
  • Social Studies (http://www.academickids.com/encyclopedia/index.php/Social_Studies)
    • Anthropology (http://www.academickids.com/encyclopedia/index.php/Anthropology)
    • Economics (http://www.academickids.com/encyclopedia/index.php/Economics)
    • Government (http://www.academickids.com/encyclopedia/index.php/Government)
    • Religion (http://www.academickids.com/encyclopedia/index.php/Religion)
    • Holidays (http://www.academickids.com/encyclopedia/index.php/Holidays)
  • Space and Astronomy
    • Solar System (http://www.academickids.com/encyclopedia/index.php/Solar_System)
    • Planets (http://www.academickids.com/encyclopedia/index.php/Planets)
  • Sports (http://www.academickids.com/encyclopedia/index.php/Sports)
  • Timelines (http://www.academickids.com/encyclopedia/index.php/Timelines)
  • Weather (http://www.academickids.com/encyclopedia/index.php/Weather)
  • US States (http://www.academickids.com/encyclopedia/index.php/US_States)

Information

  • Home Page (http://academickids.com/encyclopedia/index.php)
  • Contact Us (http://www.academickids.com/encyclopedia/index.php/Contactus)

  • Clip Art (http://classroomclipart.com)
Toolbox
Personal tools