Cerium

Cerium phase diagram

Ceric ammonium nitrate

5 mm Tinted White LED (on)

Ceres - RC3 - Haulani Crater (22381131691)

Jöns Jacob Berzelius x Johan Way

Cerium is a chemical element with the symbol Ce and atomic number 58. It is a soft, silvery-white metalloid that is the second element in the lanthanide series of the periodic table. Cerium is the most abundant of the rare earth elements and makes up about 0.0046% of the Earth's crust. It was discovered in Sweden in 1803 by Jöns Jakob Berzelius and Wilhelm Hisinger, and independently in Germany by Martin Heinrich Klaproth. The element was named after the dwarf planet Ceres, which had been discovered two years earlier.

Properties

Cerium has a melting point of 798°C and a boiling point of 3424°C. It is relatively soft, with a Mohs hardness of 2.5. Cerium has the ability to easily oxidize in the air, and it can also burn when heated or finely divided. The element has several isotopes, with cerium-140 being the most abundant and stable.

Applications

Cerium has a wide range of applications due to its physical and chemical properties. It is used in the manufacturing of glass, both as a component to prevent discoloration and as a decolorizing agent. Cerium oxide, known as ceria, is used as a polishing agent for glass and is also important in the production of catalysts, particularly in the automotive industry for catalytic converters. Additionally, cerium compounds are used in the production of phosphors for fluorescent lamps and LEDs. The metal is also used in alloys to improve the strength of magnesium and aluminum alloys.

Occurrence

Cerium is not found free in nature but is contained in several minerals, the most important being monazite and bastnäsite, which are mined for their rare earth content. These minerals contain a mixture of rare earth elements, and cerium is extracted through a series of chemical processes.

Health and Environmental Effects

While cerium is not considered highly toxic, it can cause irritation when in contact with the skin or eyes. Inhalation of cerium dust or powder can lead to respiratory issues. Environmental impacts are primarily associated with the mining and processing of cerium-bearing minerals, which can lead to habitat destruction and water pollution if not managed properly.

See Also

• Lanthanide
• Rare earth element
• Monazite
• Bastnäsite