Cerium (Ce)
Cerium is element 58, a lanthanide in period 6 of the periodic table. At room temperature it is a solid.
Electron configuration [Xe] 4f1 5d1 6s2
Electrons per shell 2, 8, 18, 19, 9, 2
Cerium data
| Atomic number | 58 |
|---|---|
| Symbol | Ce |
| Atomic mass | 140.116 u |
| Category | Lanthanide |
| Group | — (f-block) |
| Period | 6 |
| Block | f |
| State at 25 °C | solid |
| Melting point | 1071 K (797.9 °C) |
| Boiling point | 3633 K (3359.9 °C) |
| Density | 6.689 g/cm³ |
| Electronegativity (Pauling) | 1.12 |
| Atomic radius | — |
| 1st ionization energy | 534 kJ/mol |
| Electron affinity | -50 kJ/mol |
| Oxidation states | +2, +3, +4 |
| Common ion charge | 3+, 4+ |
| Discovered | 1803 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through cerium’s configuration and its ions →
Where cerium sits
Cerium belongs to the lanthanides. Its Pauling electronegativity of 1.12 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Cerium FAQ
What is the electron configuration of cerium?
Cerium (Z = 58) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f1 5d1 6s2. In noble-gas shorthand that is [Xe] 4f1 5d1 6s2. This is an exception to the simple Aufbau prediction (1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f2 5s2 5p6 6s2); a half-filled or filled subshell lowers the energy.
How many valence electrons does cerium have?
3 (2 outer s + 1 d electrons; 2 in the outermost shell).
What is the atomic mass of cerium?
The standard atomic weight of cerium is 140.116 u, so one mole weighs 140.116 g.
Is cerium a metal?
Yes. Cerium is a lanthanide.
What is the charge of a cerium ion?
Cerium most commonly forms Ce3+ or Ce4+.