Cerium
Element Name: Cerium
Atomic Number: 58
Atomic Mass: 140.116
Atomic Symbol: Ce
Melting Point: 798° C
Boiling Point: 3443° C
Cerium is a gray lustrous rare earth element. It is malleable, ductile, and soft; it is also highly reactive. It will tarnish in moist and, will readily ignite if heated above 150°C. Cerium is pyrophoric, meaning that when struck or scraped the shavings will auto-ignite, creating sparks. Cerium’s charge state can vary from 2+ to 4+ depending on the oxidization state, with the 3+ being the most common. It has the second largest liquid range of the non-reactive metals (beaten only by Thorium). It has 4 allotropes – all of which are attainable at normal pressures by varying its temperature. It also has 4 natural isotopes, one of which is stable and the others have a nearly arbitrary half-life. In total, cerium has 39 isotopes.
Interesting Facts:
The long trails of sparks sometimes used in movies when metal is dragged across a rocky surface is likely a special effect made by misch metal (of which cerium is the active component). It is named after the dwarf planet “Ceres” which is itself named after a Roman god of agriculture. It was discovered in 1803 by two Swedish chemists, Berzellus and Hisinger. Independently, Martin Klaproth of Germany discovered it but published his results after. The original sample of ceria prepared and analyzed came from cerite – rare earth mineral that also contained several other REEs that would go undiscovered for 40 years.
Sources:
Cerium is never found in its elemental form in nature. Of all the lanthanides cerium is the most common in the earth’s crust at 60 parts per million (making it roughly as common as copper). It’s found in many minerals such as monazite, bastnasite, allanite (orthrite), cerite, samarskite, hydroxylbastnasite, rhabdophane, zircon, and synchysite. The first three of that list are the most common source of it. India, Brazil, and California all have large deposits of cerium.
Industrial Uses:
Cerium is a component in misch metal along with lanthanum, neodymium, and praseodymium. Misch metal is used in the flint of cigarette lighters and gas lighters. Like many rare earths, cerium is used as a phosphor in fluorescent lighting and TVs. Cerium oxide, sometimes called jeweler’s rouge when used for polishing, has a variety of uses. It is used as a catalytic convertor to reduce emissions in cars. Similarly, it is added to diesel to reduce soot and improve engine performance. It can polish glass, and self-cleaning ovens use it. Flammacerium is an anti-burn cream. It attempts to prevent infection by not allowing the body to suppress its immune system.
References:
“Facts About Cerium.” Livescience. Livescience.com, 20 June 2013. Web. 26 July
2016.
“Cerium.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Cerium Element Facts / Chemistry.” Chemicool. Chemicool.com, 4 Oct. 2012.
Web. 26 July 2016.
Gray, Theodore W., and Nick Mann. The Elements: A Visual Exploration of Every
Known Atom in the Universe. New York: Black Dog & Leventhal, 2009. Print.