in

Cerium (Ce)

QUICK REFERENCE

  • Symbol: Ce
  • Atomic Number: 58
  • Atomic Weight: 140.116
  • Element Classification: Lanthanide
  • Discovered By: Jöns Jakob Berzelius and Wilhelm Hisinger; independently by Martin Heinrich Klaproth
  • Discovery Date: 1803
  • Name Origin: Named after the dwarf planet Ceres, discovered two years before cerium
  • Density(g/cc): 6.770
  • Melting Point: 798°C
  • Boiling Point: 3424°C
  • Appearance: Silvery, lustrous, soft, and ductile metal
  • Atomic Radius(pm): 181.8

Discovery

Cerium was discovered in 1803 by Swedish chemists Jöns Jakob Berzelius and Wilhelm Hisinger, and independently by the German chemist Martin Heinrich Klaproth. The discovery was made in the mineral known as cerite, from which they were able to isolate a new oxide they called ceria. The element was named after the dwarf planet Ceres, which had been discovered just two years earlier, in 1801.

Relation to Other Elements

Cerium is the second element in the lanthanide series, a group of metals known for their similarity to each other and their widespread use in various high-tech applications. Cerium is the most abundant of the rare earth elements and is characterized by its variable oxidation states, with +3 and +4 being the most common. This variability, particularly the stable +4 oxidation state, distinguishes cerium from most other lanthanides and underlies many of its chemical reactions and applications.

Natural Occurrence

Cerium is not found free in nature but is relatively abundant in the Earth’s crust, primarily in the minerals monazite and bastnasite, along with other rare earth elements. These minerals are mined and processed to extract cerium and other lanthanides for commercial use. The largest deposits of these minerals are found in China, the United States, India, Brazil, Australia, and other countries.

Uses

Cerium has a wide range of applications due to its chemical properties and abundance:

  • Catalysis: Cerium oxide (ceria) is used as a catalyst in automotive catalytic converters to reduce emissions by converting exhaust gases into less harmful substances. It is also used in petroleum refining and as a catalyst in self-cleaning ovens.
  • Polishing: Cerium oxide is a key component in glass polishing powders for high-quality optical surfaces, including mirrors, lenses, and glass for electronics.
  • Alloys: Cerium is added to aluminum, iron, and magnesium alloys to improve their properties, such as oxidation resistance and machinability.
  • Electronics: Cerium compounds are used in the phosphors for color television screens and fluorescent lights.
  • Others: Cerium is used in carbon arc lighting for the motion picture industry, in gas mantles for portable gas lights, and as a doping agent in fuel cells and semiconductors.

The discovery of cerium and the subsequent development of its applications have significantly impacted various industries, from environmental technology and manufacturing to electronics and energy. Its versatility and abundance ensure that cerium remains a vital element in the development of new technologies.

Lanthanum (La)

Praseodymium (Pr)