Element 58 · Lanthanide
Cerium (Ce) — Element 58
Dwarf planet Ceres
Cerium (Ce) is a lanthanide in Period 6 (f-block) of the periodic table with atomic number 58, standard atomic weight 140.12 u, and ground-state electron configuration [Xe] 4f¹ 5d¹ 6s². At standard temperature and pressure it is classified as a solid with 4 valence electrons and common oxidation states +3, +4.
Catalytic converters, polishing
What are the atomic properties and physical constants of Cerium?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 58
- Standard atomic mass
- 140.12 u
- Chemical family
- Lanthanide
- Ground-state configuration
- [Xe] 4f¹ 5d¹ 6s²
- Electrons per shell
- 2, 8, 18, 19, 9, 2
- Valence electrons
- 4
- Common ion charges / oxidation states
- +3, +4
- Phase at STP
- Solid
- Pauling electronegativity
- 1.12 Pauling
- First ionization energy
- 534 kJ/mol
- Atomic radius
- 235 pm
- Melting point
- 795 °C
- Boiling point
- 3,443 °C
- Discovery year
- 1803
- Table coordinate
- Period 6, f-block
- Radioactivity
- Has stable isotope(s)
How are electrons arranged across Cerium’s shells?
A neutral Cerium atom contains 58 electrons distributed across 6 occupied principal energy shells ([Xe] 4f¹ 5d¹ 6s²). The table below compares Cerium’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Ce | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 18 e⁻ | 18 e⁻ |
| n = 4 | N | 19 e⁻ | 32 e⁻ |
| n = 5 | O | 9 e⁻ | 50 e⁻ |
| n = 6 | P | 2 e⁻ | 72 e⁻ |
Frequently Asked Questions about Cerium (Ce)
What is the atomic mass and atomic number of Cerium (Ce)?
Cerium (Ce) has atomic number Z = 58 (58 protons in its nucleus) and an IUPAC standard atomic weight of 140.12 u. It sits in Period 6 in the f-block and is classified as a lanthanide.
What is the ground-state electron configuration of Cerium?
The neutral ground-state electron configuration of Cerium (Z = 58) is [Xe] 4f¹ 5d¹ 6s². Across its 6 occupied principal shells (n = 1 to n = 6), the electrons per shell are 2, 8, 18, 19, 9, 2, with 4 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Cerium?
Cerium commonly forms +3, +4 oxidation states or ion charges in compounds. Its Pauling electronegativity is 1.12 and its first ionization energy is 534 kJ/mol.
When was Cerium discovered and what is it used for?
Cerium was discovered in 1803 (Dwarf planet Ceres). Catalytic converters, polishing
How does Cerium compare to neighboring elements?
Other lanthanide elements: