The Element Cerium
Atomic Number: 58
Atomic Weight: 140.116
Melting Point: 1071 K (798°C or 1468°F)
Boiling Point: 3697 K (3424°C or 6195°F)
Density: 6.770 grams per cubic centimeter
Phase at Room Temperature: Solid
Element Classification: Metal
Period Number: 6
Group Number: none
Group Name: Lanthanide
What's in a name? Named for the asteroid Ceres.
Say what? Cerium is pronounced as SER-ee-em.
History and Uses:
Cerium was discovered by Jöns Jacob Berzelius and Wilhelm von Hisinger, Swedish chemists, and independently by Martin Heinrich Klaproth, a German chemist, in 1803. Cerium is the most abundant of the rare earth elements and makes up about 0.0046% of the earth's crust. Today, cerium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements.
Pure cerium will ignite if it is scratched with a sharp object, but can be safely used if combined with other materials. Cerium is one of the rare earth elements used to make carbon arc lights which are used in the motion picture industry for studio lighting and projector lights. Cerium is also a component of Misch metal, a material that is used to make flints for lighters. Cerium is also used as a catalyst to refine petroleum and as an alloying agent to make special metals.
Cerium oxide (Ce2O3 and CeO2) is a component of the walls of self cleaning ovens and of incandescent lantern mantles. Cerium oxide is also used to polish glass surfaces. Ceric sulfate (Ce(So4)2) is used in some chemical analysis processes. Other cerium compounds are used to make some types of glass as well as to remove color from glass.
Estimated Crustal Abundance: 6.65×101 milligrams per kilogram
Estimated Oceanic Abundance: 1.2×10-6 milligrams per liter
Number of Stable Isotopes: 1 (View all isotope data)
Ionization Energy: 5.539 eV
Oxidation States: +4, +3
3s2 3p6 3d10
4s2 4p6 4d10 4f1
5s2 5p6 5d1