• Class: Lanthinides
• Period: 6
• IUPAC group: 3
• Traditional: IIIa

• Discovered in: 1879 by de Boisbaudran
• Origin of name: From Samarskite, a mineral
• Historical or alternate name:

Monazite & bastnasite are the chief commercial sources

Silvery white metal. STABLE in dry air. Oxide coaTing forms on surfaces exposed to moist air.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 0.347 ppm
• Sea water: 2e-7 ppm
• Metallic meteorite: 0.142 ppm
• ConTinental crust: 3.5 ppm
• Solar photosphere: 0.72 log of abundance
• Oceanic crust: 3.3 ppm
• Solar system: 0.261 relative to Si=1.0e6

   Hazards

Metal ignites and burns readily. Reacts with water. Compounds may be toxic..

• Lower:0.01
• Upper:1.0

Samarium Physical Properties

 Transitional Data

• State: Solid
• Density: 7.520 g/cm3

 Molar enthalpy

• Atomization: 206.10 kJ mol-1
• Fusion: 10.9 kJ mol-1
• Vaporization: 164.8 kJ mol-1

 Transition points

• MelTing point: 1350.0 K
• Boiling point: 2064.0 K
• Critical temperature: 5440.0 K

 Molar properties

• Atomic weight: 150.36 g/mole
• Molar volume: 20.12 cm3 mol-1

 Crystal structure sequence

double-hex-close-packed <1190 K < body-centered-cubic < melTing point

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 69.58
  • Heat Capacity 29.54

• State: gas
  • Enthalpy 206.7
  • Gibbs function 172.8
  • Entropy 183.042
  • Heat Capacity 30.355

 Miscellaneous physical

• Electrical resistivity: 88.0 µ-ohms/cm
• Debye temperature: K
• Thermal conductivity: 13.3 W / m / K
• Coefficient of linear expansion: Coef. per K
• Mass magnetic susceptibility: 1.52e-7
• X-ray diffraction mass absorption coefficients:
• CuK: 397 (µ/p)/cm2 g-1
• MoK: 58.6 (µ/p)/cm2 g-1

Samarium Chemical Properties

 Chemical basics:

• Oxidation states: +2 +3
• Molecular wt: 150.36 g/mole

 Radii

• Covalent: 166 pm
• Atomic: 180.4 pm
• Van der Waals: pm

 Ions:

• ion: +3 pm 95.8

 Covalent bonds

 Effective nuclear charge

• Slater: 2.85
• Clementi: 8.01
• Froese-Fischer: 11.06

 Electronegativity

• Pauling:
• Allred-Rochow: 1.07

 Standard reactions

Samarium Nuclear Properties

• Known 17
• Listed 11

• Known 142 - 157
• Listed 144 - 154

• % Occ.:Natural 3.1%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 340.0 days
  • Decay mode: E.C.,
  • Source: reactor
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 103.0 E6 years
  • Decay mode: alpha,
  • Source: reactor
• Notes

• % Occ.:Natural 15.0%
• Mossbauer NRA: 19.60
• Nuclear spin/Quantum no.: 7/2
• Radioisotopes:
  • Half-life: 106.0 E9 years
  • Decay mode: alpha,
  • Source: reactor
• Notes date

• % Occ.:Natural 11.3%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 8.0 E15 years
  • Decay mode: alpha,
  • Source: reactor
• Notes

• % Occ.:Natural 13.8%
• Mossbauer NRA: 3.60
• Nuclear spin/Quantum no.: 7/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 7.4%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA: 10.50
• Nuclear spin/Quantum no.: 5/2
• Radioisotopes:
  • Half-life: 93.0 years
  • Decay mode: Beta-
  • Source: reactor
• Notes

• % Occ.:Natural 26.7%
• Mossbauer NRA: 19.50
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA: 5.74 *
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 22.7%
• Mossbauer NRA: 13.10
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• Isotope Cross-section 5820±100 barns

• Absolute sensitivity: 2.21e-4 1H=1.0
• Relative sensitivity: 1.48e-3 1H=1.0
• Receptivity: 1.28 13C=1.0
• Magnetogyric ratio: -1.1124e7 rad / T / s
• Quadropole moment: -0.208e-28 m2
• Frequency: 4.128 MHz
• Reference:

Samarium Energy Properties

Electrons

• Ground state electron configuration: [Xe] 4f6 6s2
• Electron affinity: <=50 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels