Sm Samarium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

Samarium is a chemical element with symbol Sm and atomic number 62. It is a moderately hard silvery metal that readily oxidizes in air. Being a typical member of the Lanthanide series, samarium usually assumes the oxidation state +3.
It belongs to group of the periodic table having trivial name .
Samarium Facts
Read key information and facts about element Samarium
Name | Samarium |
Atomic Number | 62 |
Atomic Symbol | Sm |
Atomic Weight | 150.36 |
Phase | Solid |
Color | Silver |
Appearance | silvery white |
Classification | Lanthanide |
Group in Periodic Table | - |
Group Name | |
Period in Periodic Table | period 6 |
Block in Periodic Table | f -block |
Electronic Configuration | [Xe] 4f6 6s2 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 24, 8, 2 |
Melting Point | 1345 K |
Boiling Point | 2076 K |
CAS Number | CAS7440-19-9 |
How to Locate Samarium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 62 to find Samarium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Samarium on periodic table look for cross section of group - and period 6 in the modern periodic table.
Samarium History
The element Samarium was discovered by P.E.L. de Boisbaudran in year 1879 in France. Samarium was first isolated by P.E.L. de Boisbaudran in 1879. Samarium derived its name from Samarskite, the name of the mineral from which it was first isolated.
Boisbaudran noted a new earth in samarskite and named it samaria after the mineral.
Samarium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Samarium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
---|---|---|
Abundance in Universe | 5 | 0.04 |
Abundance in Sun | 1 | 0.01 |
Abundance in Meteorites | 170 | 20 |
Abundance in Earth's Crust | 6000 | 820 |
Abundance in Oceans | 0.00045 | 0.000019 |
Abundance in Humans | - | - |
Crystal Structure of Samarium
The solid state structure of Samarium is Simple Trigonal.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
a | b | c |
---|---|---|
362.1 pm | 362.1 pm | 2625 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
π/2 | π/2 | 2 π/3 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
Space Group Name | R_ 3m | ![]() |
Oxidation States | Space Group Number | 166 |
Crystal Structure | Simple Trigonal |
Samarium Atomic and Orbital Properties
Samarium atoms have 62 electrons and the electronic shell structure is [2, 8, 18, 24, 8, 2] with Atomic Term Symbol (Quantum Numbers) 7F0.
Atomic Number | 62 |
Number of Electrons (with no charge) | 62 |
Number of Protons | 62 |
Mass Number | 150 |
Number of Neutrons | 88 |
Shell structure (Electrons per energy level) | 2, 8, 18, 24, 8, 2 |
Electron Configuration | [Xe] 4f6 6s2 |
Valence Electrons | 4f6 6s2 |
Valence (Valency) | 3 |
Main Oxidation States | 3 |
Oxidation States | 0, 1, 2, 3 |
Atomic Term Symbol (Quantum Numbers) | 7F0 |
Bohr Atomic Model of Samarium - Electrons per energy level

n | s | p | d | f |
---|
Ground State Electronic Configuration of Samarium - neutral Samarium atom
Abbreviated electronic configuration of Samarium
The ground state abbreviated electronic configuration of Neutral Samarium atom is [Xe] 4f6 6s2. The portion of Samarium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4f6 6s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Samarium
Complete ground state electronic configuration for the Samarium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f6 6s2
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

Atomic Structure of Samarium
Samarium atomic radius is 238 pm, while it's covalent radius is - .
Atomic Radius Calculated | 238 pm (2.38 Å) |
Atomic Radius Empirical | 185 pm (1.85 Å) |
Atomic Volume | 19.98 cm3/mol |
Covalent Radius | - |
Van der Waals Radius | - |
Neutron Cross Section | 5900 |
Neutron Mass Absorption | 4.7 |
Atomic Spectrum of Samarium
Samarium Chemical Properties: Samarium Ionization Energies and electron affinity
The electron affinity of Samarium is 50 kJ/mol.
Valence | 3 |
Electronegativity | 1.17 |
ElectronAffinity | 50 kJ/mol |
Ionization Energy of Samarium
Refer to table below for Ionization energies of Samarium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 544.5 |
2nd | 1070 |
3rd | 2260 |
4th | 3990 |
Samarium Physical Properties
Refer to below table for Samarium Physical Properties
Density | 7.353 g/cm3(when liquid at m.p density is $7.16 g/cm3) |
Molar Volume | 19.98 cm3/mol |
Elastic Properties
Young Modulus | 50 |
Shear Modulus | 20 GPa |
Bulk Modulus | 38 GPa |
Poisson Ratio | 0.27 |
Hardness of Samarium - Tests to Measure of Hardness of Element
Mohs Hardness | - |
Vickers Hardness | 412 MPa |
Brinell Hardness | 441 MPa |
Samarium Electrical Properties
Samarium is Conductor of electricity. Refer to table below for the Electrical properties ofSamarium
Electrical Conductivity | 1100000 S/m |
Resistivity | 9.4e-7 m Ω |
Superconducting Point | - |
Samarium Heat and Conduction Properties
Thermal Conductivity | 13 W/(m K) |
Thermal Expansion | 0.0000127 /K |
Samarium Magnetic Properties
Magnetic Type | Paramagnetic |
Curie Point | - |
Mass Magnetic Susceptibility | 1.11e-7 m3/kg |
Molar Magnetic Susceptibility | 1.669e-8 m3/mol |
Volume Magnetic Susceptibility | 0.00081618 |
Optical Properties of Samarium
Refractive Index | - |
Acoustic Properties of Samarium
Speed of Sound | 2130 m/s |
Samarium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Samarium
Melting Point | 1345 K (1071.85°C, 1961.33 °F) |
Boiling Point | 2076 K (1802.85°C, 3277.13 °F) |
Critical Temperature | - |
Superconducting Point | - |
Enthalpies of Samarium
Heat of Fusion | 8.6 kJ/mol |
Heat of Vaporization | 175 kJ/mol |
Heat of Combustion | - |
Samarium Isotopes - Nuclear Properties of Samarium
Samarium has 38 isotopes, with between 128 and 165 nucleons. Samarium has 5 stable naturally occuring isotopes.
Isotopes of Samarium - Naturally occurring stable Isotopes: 144Sm, 149Sm, 150Sm, 152Sm, 154Sm.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
128Sm | 62 | 66 | 128 | Synthetic | ||
129Sm | 62 | 67 | 129 | Synthetic | ||
130Sm | 62 | 68 | 130 | Synthetic | ||
131Sm | 62 | 69 | 131 | Synthetic | ||
132Sm | 62 | 70 | 132 | Synthetic | ||
133Sm | 62 | 71 | 133 | Synthetic | ||
134Sm | 62 | 72 | 134 | Synthetic | ||
135Sm | 62 | 73 | 135 | Synthetic | ||
136Sm | 62 | 74 | 136 | Synthetic | ||
137Sm | 62 | 75 | 137 | Synthetic | ||
138Sm | 62 | 76 | 138 | Synthetic | ||
139Sm | 62 | 77 | 139 | Synthetic | ||
140Sm | 62 | 78 | 140 | Synthetic | ||
141Sm | 62 | 79 | 141 | Synthetic | ||
142Sm | 62 | 80 | 142 | Synthetic | ||
143Sm | 62 | 81 | 143 | Synthetic | ||
144Sm | 62 | 82 | 144 | 3.07% | Stable | N/A |
145Sm | 62 | 83 | 145 | Synthetic | ||
146Sm | 62 | 84 | 146 | Synthetic | ||
147Sm | 62 | 85 | 147 | 14.99% | Stable | N/A |
148Sm | 62 | 86 | 148 | 11.24% | Stable | N/A |
149Sm | 62 | 87 | 149 | 13.82% | Stable | N/A |
150Sm | 62 | 88 | 150 | 7.38% | Stable | |
151Sm | 62 | 89 | 151 | Synthetic | ||
152Sm | 62 | 90 | 152 | 26.75% | Stable | N/A |
153Sm | 62 | 91 | 153 | Synthetic | ||
154Sm | 62 | 92 | 154 | 22.75% | Stable | N/A |
155Sm | 62 | 93 | 155 | Synthetic | ||
156Sm | 62 | 94 | 156 | Synthetic | ||
157Sm | 62 | 95 | 157 | Synthetic | ||
158Sm | 62 | 96 | 158 | Synthetic | ||
159Sm | 62 | 97 | 159 | Synthetic | ||
160Sm | 62 | 98 | 160 | Synthetic | ||
161Sm | 62 | 99 | 161 | Synthetic | ||
162Sm | 62 | 100 | 162 | Synthetic | ||
163Sm | 62 | 101 | 163 | Synthetic | ||
164Sm | 62 | 102 | 164 | Synthetic | ||
165Sm | 62 | 103 | 165 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-19-9 |
RTECS Number | - |
CID Number | CID23951 |
Gmelin Number | - |
NSC Number | - |