Actinium
Symbol: Ac
Atomic Number: 89
Atomic Weight: 227.0278
Electron Configuration: [Rn] 6d1 7s2
Element Classification: Radioactive Rare Earth (Actinide Series)
Discovery: Andre-Louis Debierne 1899 (France)
Word Origin: Greek: akis, aktinos (ray).
Melting Point (K): 1320
Boiling Point (K): 3470
Appearance: heavy, silvery-white metal that is highly radioactive
Atomic Radius (pm): 188
Atomic Volume (cc/mol): 22.54
Ionic Radius: 118 (+3e)
Fusion Heat (kJ/mol): (10.5)
Evaporation Heat (kJ/mol): (292.9)
Pauling Negativity Number: 1.1
First Ionizing Energy (kJ/mol): 665.5
Oxidation States: 3
Lattice Structure: Face-Centered Cubic
Lattice Constant (Å): 5.310
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)
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