Cerium (thing)

So named (Latin Ceres) in 1804 by its discoverers, Baron Jöns Jakob Berzelius and W. Hisinger, Swedish mineralogists, after the recently discovered asteroid, Ceres) A gray chemical element, the most abundant of the rare-earth metals. It is used in alloys, electronic components, and nuclear fuel.

Symbol: Ce
Atomic number: 58
Atomic weight: 140.116
Density (at room temperature and pressure): 6.77 g/cc
Melting point: 798°C
Boiling point: 3,430°C
Valence: +3, +4
Ground state electron configuration: [Xe]4f¹5d¹6s²