Cerium
The most abundant rare earth, used in catalysts and polishing.
Inside the Cerium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Cerium atom step by step.
Electron configuration
[Xe] 4f1 5d1 6s2
A neutral Cerium atom has 58 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 1068 K (795 °C)
- Boiling point
- 3716 K (3443 °C)
- Density
- 6.77 g/cm³
- Electronegativity
- 1.12 Pauling
- Atomic radius
- 185 pm
- 1st ionization energy
- 534 kJ/mol
- Category
- Lanthanides
Discovery & naming
- Discovered
- 1803
- Discovered by
- Berzelius, Hisinger, and Klaproth
- Origin of name
- The dwarf planet Ceres.
Notable uses
Catalytic converters, glass polishing, and lighter flints.
Where Cerium comes from
Stellar fusion and dying stars
Mostly built by slow neutron capture in the shells of dying low-mass stars.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 58
- Atomic mass
- 140.12
- Category
- Lanthanides
- Group · Period
- — · 6
- Block
- f-block
- Shells
- 2 · 8 · 18 · 19 · 9 · 2