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Element 71 - Lutetium (Lu)
From
Lutetia
, the ancient name for Paris; discovered 1907; heaviest of the rare earths. Although rare-earth alloys such as misch metal are relatively cheap, pure lutetium is highly expensive. With many of its chemical and physical properties unknown, it has no practical value.
Properties
Atomic Number
:
71
Atomic Weight
:
174.967
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
4d
10
4f
14
5s
2
5p
6
5d
1
6s
2
Oxidation States
(Bold most stable):
+3
Boiling Point
(K):
3668
Melting Point (K):
1936
Density
(at 300K -- g/cm
3
):
9.84
Atomic Volume (at 300K -- cm
3
/mol)
17.8
Number of stable
isotopes
:
1
Number of natural
radioactive
isotopes:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
176
-- 3.7 x 10
10
years --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.56
Atomic Radius (Å):
1.75
First
Ionization Potential
(V):
5.43
Electronegativity
(Pauling's):
1.27
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.15
Heat of Vaporization (kJ/mol):
355
Heat of Fusion (kJ/mol):
18.6
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
1.5
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
16.4
Crystal Structure:
Hexagonal
Acid
-
Base
Properties:
Slightly basic