ElementsWhat is cerium?
Cerium is a soft, grey metal and the most common of the rare earth elements. Its filings can catch fire when scratched.
What is cerium used for?
Lighter flints, polishing powder for glass and screens, catalytic converters, and self-cleaning ovens.
Where the name comes from
From Ceres, the dwarf planet discovered two years before the element.
Key facts
- Symbol
- Ce
- Atomic number
- 58
- Atomic mass
- 140.116 u
- Family
- Lanthanide
- Period
- 6
- Group
- none (f-block)
- Block
- f
- State at room temperature
- Solid
- Melting point
- 797.9 °C (1,071 K, 1,468 °F)
- Boiling point
- 3,424 °C (3,697 K, 6,195 °F)
- Density
- 6.77 g/cm³
- Electrons per shell
- 2, 8, 18, 19, 9, 2
- Electron configuration
- [Xe]6s2 4f1 5d1
- Common oxidation states
- +4, +3
- Electronegativity (Pauling)
- 1.12
- First ionisation energy
- 5.539 eV
- Electron affinity
- 0.5 eV
- Atomic radius (van der Waals)
- 235 pm
- Discovered
- 1803
Place in the periodic table
Cerium is element number 58. It sits in period 6 (row 6) of the periodic table, in the separate row of lanthanides drawn below the main table, and belongs to the f-block. Just before it comes lanthanum (57), and just after it comes praseodymium (59).
Family: Lanthanides.
Physical properties
At room temperature cerium is a solid. It melts at 797.9 °C and boils at 3,424 °C, so it stays liquid over a range of 2,626 degrees. Its density is 6.77 grams per cubic centimetre, so a one-litre block would weigh about 6.77 kilograms. By density it ranks 52nd among the 96 elements with a measured value.
Inside the atom
An atom of cerium has 58 protons in its nucleus and, when neutral, 58 electrons around it. The electrons are arranged in 6 shells: 2, 8, 18, 19, 9, 2. The outermost shell holds 2 electrons. Written in full, the electron configuration is [Xe]6s2 4f1 5d1.
Its electronegativity on the Pauling scale is 1.12. This number shows how strongly an atom pulls shared electrons towards itself: fluorine, the strongest, is 3.98. Removing one electron from an atom takes 5.539 electronvolts (about 534 kilojoules per mole). One mole of cerium weighs 140.116 grams, so a single gram contains about 4.30 × 1021 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains cerium with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.