The lustre of freshly prepared americium metal is whiter and more silvery than plutonium or neptunium prepared in the same manner. Americium is a component of the smoke detector above.
Americium appears to be more malleable than uranium or neptunium and americium tarnishes slowly in dry air at room temperature. Americium is a radioactive rare earth metal which must be handled with care to avoid contact, since it is a heavy α and γ emitter. It is named after America. The α activity of241Am is about three times that of radium. Americium is available to qualified users in the UK and in the USA.
Americium is a key component of some smoke detectors.
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of americium where known.
Density of solid: 13780 kg m-3
Molar volume: 17.63 cm3
Thermal conductivity: 10 (estimate) W m‑1 K‑1
Melting point: 1449 [1176 °C (2149 °F)] K
Boiling point: 2880 [2607 °C (4725 °F)] K
Enthalpy of fusion: 20.5 kJ mol-1
Atomic radius (empirical): 175 pm
Molecular single bond covalent radius: 166 (coordination number 3) ppm
van der Waals radius: (no data) ppm
Pauling electronegativity: 1.3 (Pauling units)
Allred Rochow electronegativity: 1.2 (Pauling units)
Mulliken-Jaffe electronegativity: (no data)
First ionisation energy: 576.38 kJ mol‑1
Second ionisation energy: 1130 kJ mol‑1
Third ionisation energy: 2090 kJ mol‑1
Universe: (no data) ppb by weight
Crustal rocks: (no data) ppb by weight
Human: (no data) ppb by weight
