The artificial element fermium is named after Nobel laureate Enrico Fermi. He built the first nuclear reactor in 1942, beginning the U.S. effort to build nuclear weapons during World War II. Fermium was first identified in the debris from an atomic bomb test in 1953. This unstable element has no known uses beyond research.

Summary of properties (Fm)

Atomic weight[257]
Discoverer (year)Seaborg, Glenn T. (1952)
Natural formmetallic solid (-)
Electron configuration[Rn] 512 s2
Melting point (ºC)1527
Boiling point (ºC)
Abundance in earth's crust (ppm)synthetic
Isotope (abundance)
Density g/cm3
Van der Waals radius (pm)245
Covalent radius (pm)167
Electronegativity (Pauling)1.3
Vaporization enthalpy (kJ/mol)-
Enthalpy of fusion (kJ/mol)-
Specific heat capacity (J/g·K) at 25ºC and 1 atm-
Thermal conductivity (W/cm·K) at 25ºC and 1 atm-
Oxidation state+3
Electron affinity (eV)
1st Ionization potential (eV)6.5000

Back to the Periodic Table of the Elements.