Cerium (Ce)
Lanthanide · f-block · period 6
Soft, silvery, iron-grey metal that tarnishes in air and can spark when scratched.
Cerium (symbol Ce) is chemical element number 58, a lanthanide in the lanthanide series (f-block), period 6 of the periodic table. Its standard atomic weight is 140.12 and its electron configuration is [Xe] 4f1 5d1 6s2. At room temperature it is a solid. The most abundant of the rare-earth elements — as common as copper.
Properties
| Atomic number | 58 |
|---|---|
| Atomic mass | 140.12 |
| Category | Lanthanide |
| Block | f-block |
| Group · Period | f-block series · 6 |
| Electron configuration | [Xe] 4f1 5d1 6s2 |
| Electrons per shell | 2, 8, 18, 19, 9, 2 |
| State at 25 °C | solid |
| Melting point | 1068 K |
| Boiling point | 3716 K |
| Density | 6.77 g/cm³ |
| Electronegativity (Pauling) | 1.12 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1803 · Berzelius, Hisinger & Klaproth |
Key facts about Cerium
- The most abundant of the rare-earth elements — as common as copper.
- Named after the dwarf planet Ceres.
- Cerium oxide is the fine polish that gives glass and gemstones their final shine.
- It is the part of a lighter flint that actually throws sparks.
What Cerium is used for
Glass and gemstone polishing, catalytic converters, self-cleaning oven coatings, lighter flints, glass decolourising.
Where it sits in the periodic table
Cerium is in the lanthanide series, period 6, of the f-block. Its electron configuration [Xe] 4f1 5d1 6s2 means its outermost shell holds 2 electrons, which is what places it here and explains much of its chemistry. See Cerium on the interactive table →
Cerium — frequently asked questions
What is Cerium used for?
Glass and gemstone polishing, catalytic converters, self-cleaning oven coatings, lighter flints, glass decolourising.
Is Cerium radioactive?
No. Cerium has at least one stable isotope and is not radioactive.
What is the electron configuration of Cerium?
Cerium has the electron configuration [Xe] 4f1 5d1 6s2, which is 2, 8, 18, 19, 9, 2 electrons per shell.
What group and period is Cerium in?
Cerium is in the lanthanide series (f-block), period 6, in the f-block. Its outer shell holds 2 electrons.
Who discovered Cerium?
Cerium was discovered in 1803 by Berzelius, Hisinger & Klaproth.