All practice pages/Interatomic theory/Elements
Element 58, a lanthanide
The most abundant rare earth, the spark in a lighter flint, and the powder that polishes glass.
Period 6, in the lanthanide row set below the main table. The other lanthanides are tinted, and every cell opens its own article.
Unusually for a lanthanide, cerium readily forms Ce⁴⁺ as well as Ce³⁺, because losing a fourth electron leaves it with the same stable electron arrangement as xenon.
More abundant in the crust than copper. It is the main rare earth in bastnäsite and monazite, mined mostly in China and at Mountain Pass, California.
Jöns Jacob Berzelius and Wilhelm Hisinger in Sweden, and independently Martin Heinrich Klaproth in Germany, found it in 1803. It was named after the asteroid Ceres, discovered two years earlier.
Cerium oxide is the standard powder for polishing glass, from lenses to phone screens. Cerium also goes into catalytic converters and self-cleaning oven walls, and ferrocerium, an alloy that throws hot sparks when scratched, makes lighter flints and fire starters.