Samarium (Sm): Electron Configuration, Properties and Uses
Samarium (Sm): Electron Configuration, Properties and Uses
Electron configuration [Xe] 6s2 4f6 · f-block, lanthanide series · period 6 · Ar 150.36
Samarium data
- Atomic number
- 62
- Relative atomic mass
- 150.36
- Group
- – (lanthanide series)
- Period
- 6
- Block
- f
- Category
- Lanthanide
- Electron configuration
- [Xe] 6s2 4f6
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f6
- Electrons per shell
- 2, 8, 18, 24, 8, 2 (K L M N O P)
- Valence electrons
- 2 (in the outer shell)
- Electronegativity (Pauling)
- 1.17
- First ionisation energy
- 5.644 eV
- Atomic radius (van der Waals)
- 229 pm
- State at room temperature
- Solid
- Melting point
- 1074 °C
- Boiling point
- 1794 °C
- Density
- 7.52 g/cm³
- Common oxidation states
- +3, +2
- Discovered
- 1879
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 18 · N 24 · O 8 · P 2
Orbital diagram (outer electrons)
About samarium
Samarium, symbol Sm, is element number 62 in the periodic table. It belongs to the lanthanide series in period 6 (f-block), usually shown below the main table. Samarium was first discovered in 1879. Samarium is a solid at room temperature, melting at 1074 °C and boiling at 1794 °C.
Samarium electron configuration
The electron configuration of samarium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f6, or in short [Xe] 6s2 4f6. Its electrons occupy 6 shells: K = 2, L = 8, M = 18, N = 24, O = 8, P = 2. As a lanthanide, samarium fills the 4f subshell. Its outer 6s subshell holds 2 electrons; valence electrons for this series are not assigned by the usual group rule. When it forms cations, electrons leave the outermost subshell first: Sm3+ = [Xe] 4f5.
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s2(12) → 3p6(18) → 4s2(20) → 3d10(30) → 4p6(36) → 5s2(38) → 4d10(48) → 5p6(54) → 6s2(56) → 4f6(62)
Uses of samarium
Well-known applications of samarium include samarium-cobalt magnets for high temperatures and Sm-153 for bone cancer pain relief.
Safety
Samarium metal is generally safe to handle, but avoid breathing its dust and read the SDS before using Samarium compounds. Always read the safety data sheet (SDS) before working with a chemical.
Other lanthanides
Frequently asked questions
What is the electron configuration of samarium?
The electron configuration of samarium (Sm, atomic number 62) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f6, or [Xe] 6s2 4f6 in short. By shell: 2, 8, 18, 24, 8, 2.
How many valence electrons does samarium have?
Samarium has 2 electrons in its outer shell. For lanthanides and actinides, valence electrons are not assigned by the usual group rule.
Which group and period is samarium in?
Samarium is in the lanthanide series, period 6, f-block.
What is the atomic mass of samarium?
The relative atomic mass of samarium is 150.36. Use it to calculate molar mass with the molar mass calculator.
Prepare solutions with analytical-grade reagents
AMI Scientific is one of the official TCI distributors in Indonesia. Reagents with lot CoA & SDS, formal quotations and tax invoices for universities and laboratories.
Other formulas & calculators: molarity, mole, molality, normality, dilution, titration, pH, buffer, molar mass, ppm, mole fraction, mass percent, periodic table, chemical MSDS.
