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Lutetium

CAS: 7439-94-3
Description: Silvery metal
Classification: Rare Earth (Lanthanide)
Date of Discovery: 1907
Discoverer: Georges Urbain
Name Origin: Lutetia, "Paris"
Alternative Name: Cassiopeium (Germany)

Atomic Number: 71
Number of Neutrons: 104
Atomic Mass: 174.967(1) amu
Melting Point: 1663 °C
Boiling Point: 3402 °C
Density (25 °C): 9.8841 g/cm3
Atomic volume: 17.78 cm3/mol
Electrical resistivity: 0.0185 10-6/cm Ohm Symbol
Thermal conductivity: 0.164 W/cmK
Enthalpy of atomization: 398 kJ/mol (est.)
Enthalpy of vaporization: 355.90 kJ/mol
Enthalpy of fusion: 18.60 kJ/mol
Specific heat capacity: 0.15 J/gK
Energy levels: 2-8-18-32-9-2
Electron configuration: [Xe]4f 145d16s2
Crystal Structure: Hexagonal
Atomic radius: 2.25 Å
Covalent radius: 1.56 Å
Oxidation States: +3
Electronegativity, Pauling: 1.27
Electron affinity:
First ionization energy: 5.43 eV
2nd ionization energy: 13.888 eV
3rd ionization energy: 20.957 eV
Polarizability: 21.9 10-24cm3
Isotope Natural Abundance Atomic Mass Half-life Decay Mode Spin
150Lu 149.973 Alpha Symbol35 ms p
151Lu 150.967 0.08 s p
152Lu 151.963 0.7 s Beta Symbol-
153Lu 152.959 Beta Symbol-
154Lu 153.9571 1.0 s Beta Symbol+, EC
155mLu 2.6 ms alpha symbol
155Lu 154.9542 0.07 s EC; alpha symbol
156mLu 0.20 s alpha symbol
156Lu 155.9529 Alpha Symbol0.5 s Beta Symbol+, EC; alpha symbol
157mLu Alpha Symbol9.6 s alpha symbol
157Lu 156.95010 4.8 s Beta Symbol+, EC; alpha symbol
158Lu 15794984 10.4 s Beta Symbol+, EC; alpha symbol
159Lu 158.9467 12.3 s Beta Symbol+, EC
160Lu 159.94654 36.1 s Beta Symbol+, EC
161Lu 160.9432 1.2 m Beta Symbol+, EC
162mLu Alpha Symbol1.5 m EC 4-
162Lu 161.9432 1.37 m Beta Symbol+, EC 1-
163Lu 162.9412 4.1 m Beta Symbol+, EC
164Lu 163.9412 3.14 m Beta Symbol+, EC
165Lu 164.9396 10.7 m Beta Symbol+, EC 1/2+
166m2Lu 2.1 m Beta Symbol+; EC (0-)
166m1Lu 1.4 m Beta Symbol+, EC; IT (3-)
166Lu 165.9398 2.8 m Beta Symbol+; EC (6-)
167Lu 166.9383 52 m Beta Symbol+; EC 7/2+
168mLu 6.7 m Beta Symbol+; EC 3+
168Lu 167.9387 5.5 m Beta Symbol+; EC (6-)
169mLu 2.7 m IT 1/2-
169Lu 168.93765 1.419 d EC 7/2+
170mLu 0.7 s IT 4-
170Lu 169.93847 2.01 d EC 0+
171mLu 1.31 m IT 1/2-
171Lu 170.937910 8.24 d EC 7/2+
172mLu 3.7 m IT 1-
172Lu 171.939082 6.70 d EC 4-
173Lu 172.938927 1.37 y EC 7/2+
174mLu 142 d IT; EC 6-
174Lu 173.940334 3.3 y EC 1-
175Lu 97.41(2) 174.940768 Stable 7/2+
176mLu 3.66 h Beta Symbol- 1-
176Lu 2.59(2) 175.942683 3.8 x 1010 y Beta Symbol- 7-
177mLu 160.7 d IT; Beta Symbol- 23/2-
177Lu 176.943755 6.75 d Beta Symbol- 7/2+
178mLu 23.1 m Beta Symbol- (9-)
178Lu 177.945952 28.5 m Beta Symbol- 1+
179Lu 178.94732 4.6 h Beta Symbol- 7/2+
180Lu 179.9499 5.7 m Beta Symbol-
181Lu 180.9518 3.5 m Beta Symbol- (7/2+)
182Lu 2.0 m Beta Symbol-
183Lu 58 s Beta Symbol- 7/2+
In 1907, Urbain described a process by which Marignac's ytterbium (1879) could be separated into the two elements, ytterbium (neoytterbium)and lutetium. These elements were identical with "aldebaranium" and "cassiopeium," independently discovered by von Welsbach about the same time. Charles James of the University of New Hampshire also independently prepared the very pure oxide, lutecia, at this time. The spelling of the element was changed from lutecium to lutetium in 1949. Lutetium occurs in very small amounts in nearly all minerals containing yttrium, and is present in monazite to the extent of about 0.003%, which is a commercial source. The pure metal has been isolated only in recent years and is one of the most difficult to prepare. It can be prepared by the reduction of anhydrous LuCl3 or LuF3 by an alkali or alkaline earth metal. The metal is silvery white and relatively stable in air. While new techniques, including ion-exchange reactions, have been developed to separate the various rare-earth elements, lutetium is still the most costly of all rare earths. 176Lu occurs naturally (97.41 %) with 175Lu (2.59%), which is radioactive with a very long half-life. It is radioactive with a half-life of about 4 x 1010 years. Lutetium has 49 isotopes and isomers that are now recognized. Stable lutetium nuclides, which emit pure beta radiation after thermal neutron activation, can be used as catalysts in cracking, alkylation, hydrogenation, and polymerization. Virtually no other commercial uses have been found yet for lutetium. While lutetium, like other rare-earth metals, is thought to have a low toxicity rating, it should be handled with care until more information is available.
LINKS:

Information, data sheet and standard forms
A lutetium product supplier
Photon Interaction Coefficients of Lutetium


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Sources for the information on this website include:
Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998.