What does cerium mean?
Cerium is a soft, silvery metallic element and the most abundant of the rare-earth metals. A member of the lanthanide series with the atomic number 58 and the symbol Ce, it is found in minerals such as bastnäsite and monazite. Although classed as a rare earth, cerium is actually more plentiful in the Earth's crust than copper. The element is remarkably reactive: its alloy with iron, used in lighter flints, produces bright sparks when scraped, while cerium oxide serves as a polishing agent for glass and as a catalyst in automotive exhaust systems. The word derives from Ceres, the asteroid discovered in 1801, whose own name comes from the Roman goddess of agriculture. Cerium appears chiefly in scientific, industrial, and technical writing rather than everyday conversation, but it plays a significant role in modern technology.
nounA soft, silvery, ductile metallic element that is the most abundant of the rare-earth elements; it is a lanthanide with the atomic number 58 and symbol Ce.
- The chemical element cerium (symbol Ce), atomic number 58 — a silvery, malleable lanthanide metal, the most abundant rare-earth element.
"Cerium oxide is widely used as a polishing agent for glass and optical lenses."
"Lighter flints contain mischmetal, an alloy rich in cerium that sparks when struck."
"The chemists isolated cerium from the mineral bastnäsite in the early nineteenth century."
As a chemical element name, cerium is normally uncountable and has no plural form. It would only be pluralized informally when referring to distinct atoms or isotopes in a technical context.
"The sample contained traces of cerium alongside other rare-earth elements."
Named after an asteroid before anyone had even landed on the Moon: cerium was christened in 1803 after Ceres, the newly discovered dwarf planet between Mars and Jupiter.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cerium
Cerium was discovered in 1803, independently by Jöns Jacob Berzelius and Wilhelm Hisinger in Sweden and by Martin Heinrich Klaproth in Germany. It was named after the dwarf planet Ceres, which had been discovered just two years earlier in 1801 — making cerium one of the few elements named after an astronomical body. Ceres itself takes its name from the Roman goddess of agriculture, from the Latin root that also gives English words like 'cereal'.
Related word forms
How cerium is actually used
A technical term used mainly in chemistry, physics, materials science, and industrial contexts. It is uncountable when referring to the element itself. Its compounds are often named with the adjectives 'ceric' (cerium in the +4 oxidation state) and 'cerous' (+3 oxidation state).
Easily confused with cerium
Cesium (Cs) is a different chemical element — a highly reactive alkali metal — whereas cerium (Ce) is a lanthanide rare earth metal.