Return
to the Main CHEMystery Page.
Return
to the Periodic Table of the Elements
Element 58 - Cerium (Ce)
After the asteroid Ceres; discovered 1803; most abundant of the rare-earth elements. It is the chief ingredient (just under 50 percent) of misch-metal alloy. Cerium is used in alloy to make heat-resistant jet-engine parts; its oxide is a promising new petroleum cracking catalyst.
Properties
Atomic Number
:
58
Atomic Weight
:
140.12
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
4d
10
4f
2
5s
2
5p
6
6s
2
Oxidation States
(Bold most stable):
+3
, +4
Boiling Point
(K):
3715
Melting Point (K):
1071
Density
(at 300K -- g/cm
3
):
6.77
Atomic Volume (at 300K -- cm
3
/mol)
21.0
Number of stable
isotopes
:
4
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
144 -- 284 days --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.65
Atomic Radius (Å):
1.81
First
Ionization Potential
(V):
5.47
Electronegativity
(Pauling's):
1.12
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.19
Heat of Vaporization (kJ/mol):
313.8
Heat of Fusion (kJ/mol):
9.20
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
1.4
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
11.4
Crystal Structure:
Cubic, face centered
Acid
-
Base
Properties:
Very basic