Sm
Samarium
Element 62 · Lanthanide
Samarium (Sm)
Samarium is a silvery rare-earth metal used in heat-resistant magnets and in cancer pain relief.
- Lanthanide
- Period 6
- f-block series
- f-block
- solid at room temperature
Key properties
- Atomic mass
- 150.4
- u
- Electron configuration
- [Xe] 4f6 6s2
- Melting point
- 1,073.9 °C
- 1,347 K
- Boiling point
- 1,793.9 °C
- 2,067 K
- Density
- 7.52 g/cm³
- Electronegativity
- 1.17
- Pauling
- Atomic radius
- 229 pm
- van der Waals
- 1st ionisation energy
- 5.644 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about samarium
- 01
It was the first element named, indirectly, after a person.
- 02
Samarium–cobalt magnets keep their strength at temperatures above 300 °C.
- 03
Samarium-153 is used to relieve the pain of cancer that has spread to the bones.
Applications
What is samarium used for?
- Samarium–cobalt magnets
- Cancer pain treatment
- Neutron absorbers
- Infrared-absorbing glass
History
Discovery & name origin
Discovered by
Year
Where
France
Name origin
From the mineral samarskite, named after mining engineer Vasili Samarsky-Bykhovets.
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 62
- Atomic mass
- 150.4 u
- Group
- Lanthanides (3)
- Period
- 6
- Block
- f-block
- Electron configuration
- [Xe] 4f6 6s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f6
- Electrons per shell
- 2, 8, 18, 24, 8, 2
- Electronegativity (Pauling)
- 1.17
- Electron affinity
- —
- Atomic radius (van der Waals)
- 229 pm
- Stable isotopes
- 5
Oxidation states
Highlighted: common oxidation states (+3, +2).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st544.5
- 2nd1,070
- 3rd2,260
- 4th3,990
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 1,347 K · 1,073.9 °C · 1,964.9 °F
- Boiling point
- 2,067 K · 1,793.9 °C · 3,260.9 °F
- Density
- 7.52 g/cm³
- Molar heat capacity
- 29.54 J/(mol·K)
- Appearance
- Silvery white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Samarium questions
What is Sm on the periodic table?
Sm is the symbol for samarium, element 62 on the periodic table. It sits in period 6, in the f-block, in the lanthanide category, and has an atomic mass of 150.4.
What is the atomic number of samarium?
Samarium has atomic number 62, so every samarium atom has 62 protons in its nucleus. Its symbol is Sm and its atomic mass is 150.4.
Who discovered samarium?
Samarium was discovered by Paul-Émile Lecoq de Boisbaudran in 1879 (France). The name comes from from the mineral samarskite, named after mining engineer Vasili Samarsky-Bykhovets.
What is samarium used for?
Samarium is used for: samarium–cobalt magnets; cancer pain treatment; neutron absorbers; infrared-absorbing glass.
Is samarium a metal?
Yes. Samarium is a lanthanide, one of the metallic elements.
What is the electron configuration of samarium?
The electron configuration of samarium is [Xe] 4f6 6s2. Its 62 electrons are arranged in shells as 2, 8, 18, 24, 8, 2.