058Lanthanide · Group 3 · Period 6
Cerium
Cerium (Ce) is element 58, a lanthanide in the f-block — group 3, period 6. It is a solid at room temperature with 6 electron shells (2, 8, 18, 19, 9, 2) and an atomic mass of 140.1161 u.
- Atomic mass
- 140.1 u
- Phase · STP
- solid
- Melting
- 1068 K · 795 °C
- Boiling
- 3716 K · 3443 °C
- Electronegativity
- 1.12
- Density
- 6.77 g/cm³
Photograph — Jurii, CC BY 1.0 <https://creativecommons.org/licenses/by/1.0>, via Wikimedia Commons, source: https://images-of-elements.com/cerium.php
Identity
- Atomic number
- 58
- Standard atomic weight
- 140.1 u
- Category
- Lanthanide
- Group
- 3
- Period
- 6
- Block
- f-block
- Oxidation states
- +4, +3
Physical properties
- Melting point
- 1068 K · 795 °C
- Boiling point
- 3716 K · 3443 °C
- Density
- 6.77 g/cm³
- Molar heat capacity
- 26.94 J/(mol·K)
- Atomic radius
- 235 pm
- Electron affinity
- 55 kJ/mol
Atomic structure
58protons
82neutrons
58electrons
2valence e⁻
- Noble-gas notation
- [Xe] 4f1 5d1 6s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d1 4f1
- Electrons per shell
- 2, 8, 18, 19, 9, 2
Periodic trends
Where Cerium ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
534.41
1.1k2
1.9k3
3.5k4
6.3k5
7.5k6
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1803
- Discovered by
- Martin Heinrich Klaproth
- Named by
- —
- Appearance
- silvery white