Cerium

a steel-gray, ductile metallic element of the rare-earth group found only in combination. Symbol: Ce; atomic weight: 140.12; atomic number: 58.
Contemporary Examples

Historical Examples

noun
a malleable ductile steel-grey element of the lanthanide series of metals, used in lighter flints and as a reducing agent in metallurgy. Symbol: Ce; atomic no: 58; atomic wt: 140.115; valency: 3 or 4; relative density: 6.770; melting pt: 798°C; boiling pt: 3443°C
n.

element, first isolated in pure form in 1875, named for ceria, the name of the earth from which it was taken, which was discovered in 1803 and named by Berzelius and Hissinger for Ceres, the minor planet, which had been discovered in 1801 and named for the Roman goddess Ceres.

cerium ce·ri·um (sēr’ē-əm)
n.
Symbol Ce
A lustrous, malleable metallic rare-earth element that occurs chiefly in the minerals monazite and bastnaesite, exists in four allotropic states, and is used in lighter flint alloys. Atomic number 58; atomic weight 140.12; melting point 799°C; boiling point 3,424°C; specific gravity 6.67; valence 3, 4.
cerium
(sîr’ē-əm)
Symbol Ce
A shiny, gray metallic element of the lanthanide series. It is ductile and malleable and is used in electronic components, alloys, and lighter flints. It is also used in glass polishing and as a catalyst in self-cleaning ovens. Atomic number 58; atomic weight 140.12; melting point 795°C; boiling point 3,468°C; specific gravity 6.67 to 8.23; valence 3, 4. See Periodic Table.