Cerium (Ce)
Lanthanide
Cerium is the most abundant rare-earth element — about as common in the crust as copper. It sparks in lighter flints, polishes glass and mirrors, and cleans up diesel exhaust as a catalyst.
Position on the periodic table
Atomic properties
| Atomic number | 58 |
|---|---|
| Atomic mass | 140.116 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d1 4f1 |
| Noble gas shorthand | [Xe] 4f1 5d1 6s2 |
| Electrons per shell | 2, 8, 18, 19, 9, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | +3, +4 |
| Electronegativity (Pauling) | 1.12 |
| Covalent radius (approx.) | 204 pm |
| First ionization energy | 534.4 kJ/mol |
| Electron affinity | 55 kJ/mol |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 6.77 g/cm³ |
| Melting point | 794.85 °C (1068 K) |
| Boiling point | 3442.8 °C (3716 K) |
| Appearance | silvery white |
| Radioactive | No |
| Origin | Occurs naturally |
Electron configuration of cerium
Cerium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d1 4f1, usually shortened to [Xe] 4f1 5d1 6s2. Its electrons occupy 6 shells (2, 8, 18, 19, 9, 2), placing it in period 6 of the f-block. Explore it interactively in the electron configuration calculator.
Uses of cerium
- Lighter flints (mischmetal alloy)
- Glass polishing powder (CeO₂)
- Diesel fuel additives and catalytic coatings
- UV-blocking glass
Biological role: None known.
Occurrence: The most common rare earth, from bastnäsite and monazite.
Common compounds of cerium
CeO2
Cerium(IV) oxide (ceria)
History and discovery
Discovered: 1803 — Martin Heinrich Klaproth. Name origin: Named after the asteroid (now dwarf planet) Ceres, discovered two years earlier.
Discovered in 1803 by Berzelius and Hisinger in Sweden and independently by Klaproth in Germany.
Safety notes
Low toxicity; the sparking alloy is an obvious fire source.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Cerium
1. What is the chemical symbol of Cerium?
2. What is the atomic number of Cerium?
3. Which category does Cerium belong to?
4. What is the state of Cerium at room temperature?
5. Which period of the periodic table is Cerium in?
Cerium FAQs
What is the atomic number of cerium?
Cerium's atomic number is 58 — every cerium atom has 58 protons in its nucleus.
What is the symbol for cerium?
Ce. Named after the asteroid (now dwarf planet) Ceres, discovered two years earlier.
Is cerium a metal, nonmetal, or metalloid?
Cerium is classified as a lanthanide.
What state is cerium at room temperature?
At about 25 °C, cerium is a solid. It melts at 794.85 °C.
What is cerium used for?
Key uses include: lighter flints (mischmetal alloy); glass polishing powder (ceo₂); diesel fuel additives and catalytic coatings.
Related elements
Keep working with this element
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