Americium

OccurrenceAmericium does not exist in nature. All of its isotopes are man-made and radioactive.Americium-241 is produced by bombarding plutonium-239 with high-energy neutrons,resulting in the isotope plutonium-240 that again is bombarded with neutrons and resultsin the formation of plutonium-241, which in turn finally decays into americium-241 by theprocess of beta decay. Both americium-241 and americium-243 are produced within nuclearreactors. The reaction is as follows: 239Pu + (neutron and λ gamma rays) → 240Pu + (neutronand λ gamma rays) → 241Pu→ 241Am + beta minus (β-); followed by 241Am→ 93Np-237 +4He2 (helium nuclei).

VerwendenGamma radiography, radiochemical research, diagnostic aid, electronic devices.

DefinitionAm. A synthetic radioactive element of atomic number 95, a member of the actinide series; aw 241; 14 isotopes of widely varying half-life; valence 3, but divalent, tetravalent, and higher valencies exist. α and γ emitter, forms compounds with oxygen, halides, lithium, etc. Metallic americium is silver-white crystalline, d 13.6, mp approximately 100C. Half-life of 241 Am is 458 years.