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94Pu244.000
Plutonium
ActinidePlutonium is a transuranic radioactive chemical element with symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states.
Phase: SolidAppearance: silvery white, tarnishing to dark gray in air
2, 8, 18, 32, 24, 8, 2
Physical Properties
Atomic Mass244 u
Density19.816 g/cm³
Melting Point912.5 K
Boiling Point3505 K
Molar Heat35.5 J/(mol·K)
Period7
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f6
Semantic Config[Rn] 5f6 7s2
Shells2, 8, 18, 32, 24, 8, 2
Electron Affinity-48.33 kJ/mol
Electronegativity1.28
Ionization Energies
IE1: 584.7 kJ/mol
Discovery
Discovered byGlenn T. Seaborg