Element 62 · Lanthanide
Samarium (Sm) — Element 62
Mineral samarskite
Samarium (Sm) is a lanthanide in Period 6 (f-block) of the periodic table with atomic number 62, standard atomic weight 150.36 u, and ground-state electron configuration [Xe] 4f⁶ 6s². At standard temperature and pressure it is classified as a solid with 3 valence electrons and common oxidation states +3, +2.
Magnets, cancer therapy
What are the atomic properties and physical constants of Samarium?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 62
- Standard atomic mass
- 150.36 u
- Chemical family
- Lanthanide
- Ground-state configuration
- [Xe] 4f⁶ 6s²
- Electrons per shell
- 2, 8, 18, 24, 8, 2
- Valence electrons
- 3
- Common ion charges / oxidation states
- +3, +2
- Phase at STP
- Solid
- Pauling electronegativity
- 1.17 Pauling
- First ionization energy
- 545 kJ/mol
- Atomic radius
- 229 pm
- Melting point
- 1,072 °C
- Boiling point
- 1,794 °C
- Discovery year
- 1879
- Table coordinate
- Period 6, f-block
- Radioactivity
- Has stable isotope(s)
How are electrons arranged across Samarium’s shells?
A neutral Samarium atom contains 62 electrons distributed across 6 occupied principal energy shells ([Xe] 4f⁶ 6s²). The table below compares Samarium’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Sm | 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 | 24 e⁻ | 32 e⁻ |
| n = 5 | O | 8 e⁻ | 50 e⁻ |
| n = 6 | P | 2 e⁻ | 72 e⁻ |
Frequently Asked Questions about Samarium (Sm)
What is the atomic mass and atomic number of Samarium (Sm)?
Samarium (Sm) has atomic number Z = 62 (62 protons in its nucleus) and an IUPAC standard atomic weight of 150.36 u. It sits in Period 6 in the f-block and is classified as a lanthanide.
What is the ground-state electron configuration of Samarium?
The neutral ground-state electron configuration of Samarium (Z = 62) is [Xe] 4f⁶ 6s². Across its 6 occupied principal shells (n = 1 to n = 6), the electrons per shell are 2, 8, 18, 24, 8, 2, with 3 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Samarium?
Samarium commonly forms +3, +2 oxidation states or ion charges in compounds. Its Pauling electronegativity is 1.17 and its first ionization energy is 545 kJ/mol.
When was Samarium discovered and what is it used for?
Samarium was discovered in 1879 (Mineral samarskite). Magnets, cancer therapy
How does Samarium compare to neighboring elements?
Other lanthanide elements: