95
243.00
Am
Americium
Identification
CAS Number: 7440-35-9
Discovery Year: 1945
Discoverer: G.T.Seaborg, R.A.James, L.O.Morgan, A.Ghiorso
Discovery Location: United States
Properties
Atomic Dimensions
Atomic Radius: 175 pm →
Atomic Radius (Rahm): 276 pm
Covalent Radius: 180 pm →Van der Waals Radius: 244 pm
Atomic Volume: 20.8 cm³/mol
Thermodynamics
Melting Point: 1267 K →Boiling Point: 2880 K →Heat of Fusion: 10 kJ/mol →Heat of Vaporization: 238.5 kJ/mol →
Heat of Formation: 284 kJ/mol
Electronic Structure
Abundance & Geochemistry
Goldschmidt Class: synthetic
About
Radioactive metallic transuranic element, belongs to the actinoids. Ten known isotopes. Am-243 is the most stable isotope, with a half-life of 7.95*10^3 years. Discovered by Glenn T. Seaborg and associates in 1945, it was obtained by bombarding Uranium-238 with alpha particles.
Isotopes
Am-241 241 ☢ 433 a
Am-243 243 ☢ 7.37e+3 a
