Neodymium

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Neodymium
60Nd
-

Nd

U
praseodymiumneodymiumpromethium
Appearance
silvery white
General properties
Name, seembol, nummer neodymium, Nd, 60
Pronunciation /ˌn.ɵˈdɪmiəm/
NEE-o-DIM-ee-əm
Element category lanthanide
Group, period, block n/a, 6, f
Staundart atomic wicht 144.242
Electron confeeguration [Xe] 4f4 6s2
2, 8, 18, 22, 8, 2
Electron shells of neodymium (2, 8, 18, 22, 8, 2)
History
Discovery Carl Auer von Welsbach (1885)
Physical properties
Phase solid
Density (near r.t.) 7.01 g·cm−3
Liquid density at m.p. 6.89 g·cm−3
Meltin pynt 1297 K, 1024 °C, 1875 °F
Boilin pynt 3347 K, 3074 °C, 5565 °F
Heat o fusion 7.14 kJ·mol−1
Heat o vaporization 289 kJ·mol−1
Molar heat capacity 27.45 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1595 1774 1998 (2296) (2715) (3336)
Atomic properties
Oxidation states 3, 2, 1

(mildly basic oxide)

Electronegativity 1.14 (Pauling scale)
Ionization energies 1st: 533.1 kJ·mol−1
2nd: 1040 kJ·mol−1
3rd: 2130 kJ·mol−1
Atomic radius 181 pm
Covalent radius 201±6 pm
Miscellanea
Crystal structure hexagonal
Neodymium has a hexagonal crystal structure
Magnetic orderin paramagnetic, antiferromagnetic ablo 20 K[1]
Electrical resistivity (r.t.) (α, poly) 643 nΩ·m
Thermal conductivity 16.5 W·m−1·K−1
Thermal expansion (r.t.) (α, poly) 9.6 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2330 m·s−1
Young's modulus (α form) 41.4 GPa
Shear modulus (α form) 16.3 GPa
Bulk modulus (α form) 31.8 GPa
Poisson ratio (α form) 0.281
Vickers hairdness 343 MPa
Brinell hairdness 265 MPa
CAS registry nummer 7440-00-8
Most stable isotopes
Main article: Isotopes o neodymium
iso NA hauf-life DM DE (MeV) DP
142Nd 27.2% - (SF) <53.264
143Nd 12.2% - (α) 0.5214 139Ce
144Nd 23.8% 2.29×1015 y α 1.905 140Ce
145Nd 8.3% >6×1016 y (α) 1.5784 141Ce
146Nd 17.2% - (α) 1.1822 142Ce
(ββ) 0.0702 146Sm
148Nd 5.7% >3.0×1018 y (α) 0.5986 144Ce
(ββ) 1.9288 148Sm
150Nd 5.6% 6.7×1018 y ββ 3.367 150Sm
Decay modes in parentheses are predictit, but hae nae yet been observed
· r

Neodymium is a chemical element wi the seembol Nd an atomic nummer 60. It is a saft sillery metal that tarnishes in air. Neodymium wis discovered in 1885 bi the Austrian chemist Carl Auer von Welsbach. It is present in signeeficant quantities in the ore minerals monazite an bastnäsite. Neodymium is nae foond naiturally in metallic furm or unmixed wi ither lanthanides, an it is usually refined for general uise. Altho neodymium is classed as a "rare yird", it is a fairly common element, na rarer nor cobalt, nickel, an copper, an is widely distributit in the Yird's crust.[2] Maist o the warld's neodymium is mined in Cheenae.

References[eedit | eedit soorce]

  1. Gschneidner, K. A.; Eyring, L. (1978). Handbook on the Physics and Chemistry of Rare Earths. Amsterdam: North Holland. ISBN 0444850228. 
  2. See Abundances o the elements (data page)