Samarium
A rare earth used in heat-stable magnets and reactors.
Inside the Samarium 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 Samarium atom step by step.
Electron configuration
[Xe] 4f6 6s2
A neutral Samarium atom has 62 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
- 1345 K (1072 °C)
- Boiling point
- 2067 K (1794 °C)
- Density
- 7.52 g/cm³
- Electronegativity
- 1.17 Pauling
- Atomic radius
- 185 pm
- 1st ionization energy
- 545 kJ/mol
- Category
- Lanthanides
Discovery & naming
- Discovered
- 1879
- Discovered by
- Paul-Émile Lecoq de Boisbaudran
- Origin of name
- The mineral samarskite.
Notable uses
High-temperature magnets and cancer treatments.
Where Samarium comes from
Several comparable sources
Both slow neutron capture in dying stars and rapid capture in explosive events contribute meaningfully.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 62
- Atomic mass
- 150.36
- Category
- Lanthanides
- Group · Period
- — · 6
- Block
- f-block
- Shells
- 2 · 8 · 18 · 24 · 8 · 2