H' at. wt. (natural) 1.007967
at. wt. (H') 1.007822
at. no. 1
m.p. - 259.140C
b.p. - 252.870C
density 0.08988 gm./l
density (liquid) 70.8 gm/i. (-2530C)
density (solid) 7016 gm/i. (-2620C)
valence 1.
Electronic configuration
| K |
L |
M |
N |
O |
P |
Q |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| s |
s p |
s p d |
s p d f |
s p d f |
s p d f |
s p d f |
| 1 |
|
|
|
|
|
|
LUTETIUM (Lutetia, ancient name for Paris-some-
times called cassiopelum by the Germans). Lu; at. wt.
174.97; at. no.71; m.p. 1656j50C; b.p. 33150C; sp. gr.
9.835 (250C); valence 3. 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 "aldebar-
anium" 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 LuCI3 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
naturally occurring rare earths. It is slightly more abundant
than thulium. It is now priced at about œ26/gm. or $8000/lb.
Lu'76 occurs naturally (2.6%) with Lu'75 (97.4%). It is
radioactive with a halfAife of about 3 x 1010 yrs. Stable
lutetium nuclides, which emit pure beta radiation after
thermal neutron activation, can be used as a catalyst in
cracking, alkylation, hydrogenation, and polymerization.
Virtually no other commercial uses have been found yet for
B-19
lutetium, as it is still one of the most costly natural elements.
Lutetium, like other rare earth metals, has a low toxicity
rating. It should be handled with care.
© 1999 F. Davies
Delphi O.E.M. Co.
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