Cerium

Images

Image

Attribution: images-of-elements.com

Animated Cerium

History

Cerium was named for the asteroid Ceres, which was discovered in 1801. The element was discovered two years later in 1803 by Klaproth and by Berzelius and Hisinger. In 1875 Hillebrand and Norton prepared the metal.

Sources

Cerium is the most abundant so-called rare-earth metals. It is found in a number of minerals including allanite (also known as orthite), monazite, bastnasite, cerite, and samarskite. Monazite and bastnasite are presently the more important sources of cerium.

Large deposits of monazite (found on the beaches of Travancore, India and in river sands in Brazil), allanite (in the western United States), and bastnasite (in Southern California) will supply cerium, thorium, and the other rare-earth metals for many years to come.

Metallic cerium is prepared by metallothermic reduction techniques, such as reducing cerous fluoride with calcium, or using electrolysis of molten cerous chloride or others processes. The metallothermic technique produces high-purity cerium.

Uses

Cerium is a component of misch metal, which is extensively used in the manufacture of pyrophoric alloys for cigarette lighters. While cerium is not radioactive, the impure commercial grade may contain traces of thorium, which is radioactive. The oxide is an important constituent of incandescent gas mantles and is emerging as a hydrocarbon catalyst in self cleaning ovens where it can be incorporated into oven walls to prevent the collection of cooking residues.

As ceric sulfate is used extensively as a volumetric oxidizing agent in quantitative analysis. Cerium compounds are used in the manufacture of glass, both as a component and as a decolorizer.

The oxide is finding increased use as a glass polishing agent instead of rouge, for it polishes much faster than rouge. Cerium, with other rare earths, is used in carbon-arc lighting, especially in the motion picture industry. It is also useful as a catalyst in petroleum refining and in metallurgical and nuclear applications.

General Info

AtomicNumber
58
Symbol
Ce
Name
Cerium

Atomic Info

Appearance
AtomicWeight
140.116(1)
Color
FFFFC7
ElectronicConfiguration
[Xe] 4f1 5d1 6s2
ElectronegativityInPauling
1.12
AtomicRadiusInPM
IonRadiusInPM
102 (+3)
VanDerWaalsRadiusInPM
IEinKJmol
534
EAinKJmol
-50
OxidationStates
2, 3, 4
StandardState
solid
BondingType
metallic
MeltingPoint
1071
BoilingPoint
3633
Density
6.69
State
Lanthanide
DiscoveredYear
1803