History and Production
The name is derived from Americas. It was first produced in 1944 by G.T. Seaborg, R.A. James, L.O. Morgan and A. Ghiorsoas the result of successive bombardment of neutron on 239Pu.
The metal can be produced by reduction of americium fluoride (AmF3) with barium. 241Am is used as a portable source for gamma radiography. It has also been used as a radioactive glass thickness gauge for the flat glass industry and as a source of
ionization for smoke detectors.
It is silvery radioactive metal that slowly tarnishes in air. It appears to be more malleable than uranium and neptunium. Americium is thought to exist in two allotropic forms.
Interatomic distance: -
Melting point: 1176°C
Boiling point: 2011°C
Thermal conductivity/Wm-1K-1: 10 est. (27°C)
Density/kgm-3: 13670 (20°C)
Standard Thermodynamic Data (atomic gas)
Enthalpy of formation: -
Gibbs free energy of formation: -
Heat capacity: -
Electronic configuration: [Rn] 5f7 7s2
Term symbol: 8S7/2
Electron affinity: - Electronegativity (Pauline): -
Ionization energy (first, second, third): 576.384, -, - kJ/mol