• Class: Trans-Uranium AcTinides
• Period: 7
• IUPAC group: 3
• Traditional: IIIa

• Discovered in: 1952 by Ghiorso
• Origin of name: Enrico Fermi
• Historical or alternate name:

• Atmosphere: ~0.0 ppm
• Primitive mantle: ~0.0 ppm
• Sea water: ~0.0 ppm
• Metallic meteorite: ~0.0 ppm
• ConTinental crust: ~0.0 ppm
• Solar photosphere: ~0.0 log of abundance
• Oceanic crust: ~0.0 ppm
• Solar system: ~0.0 relative to Si=1.0e6

   Hazards

Radioactive..

• Lower:
• Upper:

Fermium Physical Properties

 Transitional Data

• State: Solid
• Density: g/cm3

 Molar enthalpy

• Atomization: 141.0 kJ mol-1
• Fusion: kJ mol-1
• Vaporization: kJ mol-1

 Transition points

• MelTing point: K
• Boiling point: K
• Critical temperature: K

 Molar properties

• Atomic weight: 257.0951 g/mole
• Molar volume: cm3 mol-1

 Crystal structure sequence

 Thermodynamics

 Miscellaneous physical

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

Fermium Chemical Properties

 Chemical basics:

• Oxidation states: +3 +4
• Molecular wt: 257.0951 g/mole

 Radii

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

 Ions:

• ion: +3 pm 93.0
• ion: +4 pm 80.0

 Covalent bonds

 Effective nuclear charge

• Slater: 1.65
• Clementi:
• Froese-Fischer:

 Electronegativity

• Pauling:
• Allred-Rochow:

 Standard reactions

Fermium Nuclear Properties

• Known 10
• Listed 1

• Known 248 - 257
• Listed

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 101.0 days
  • Decay mode: alpha, S.F.
  • Source:
• Notes

• Isotope 255Cross-section 26±3 barns

Fermium Energy Properties

Electrons

• Ground state electron configuration: [Rn] 5f12 7s2
• Electron affinity: kJ mol-1
• Filling orbitals:

 Ionization energies

 Atomic energy levels