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95Am243.000
Americium
ActinideAmericium is a radioactive transuranic chemical element with symbol Am and atomic number 95. This member of the actinide series is located in the periodic table under the lanthanide element europium, and thus by analogy was named after the Americas. Americium was first produced in 1944 by the group of Glenn T.Seaborg from Berkeley, California, at the metallurgical laboratory of University of Chicago.
Phase: SolidAppearance: silvery white
2, 8, 18, 32, 25, 8, 2
Physical Properties
Atomic Mass243 u
Density12 g/cm³
Melting Point1449 K
Boiling Point2880 K
Molar Heat62.7 J/(mol·K)
Period7
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f7
Semantic Config[Rn] 5f7 7s2
Shells2, 8, 18, 32, 25, 8, 2
Electron Affinity9.93 kJ/mol
Electronegativity1.13
Ionization Energies
IE1: 578 kJ/mol
Discovery
Discovered byGlenn T. Seaborg