Actinium is chemical element 89 on the periodic table . Its symbol is Ac . Actinium's mass is 227 g/mol.
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Actinium, 00 Ac Pronunciation (ak-TIN -ee-əm ) Appearance silvery-white, glowing with an eerie blue light;[1] sometimes with a golden cast[2] Mass number [227]
Group f-block groups (no number)Period period 7 Block f-block Electron configuration [ Rn ] 6d1 7s2 Electrons per shell 2, 8, 18, 32, 18, 9, 2 Phase at STP solid Melting point 1500 K (1227 °C, 2240 °F) (estimated) [2] Boiling point 3500±300 K (3200±300 °C, 5800±500 °F) (extrapolated) [2] Density (near r.t. ) 10 g/cm3 Heat of fusion 14 kJ/mol Heat of vaporization 400 kJ/mol Molar heat capacity 27.2 J/(mol·K) Oxidation states +3 (a strongly basic oxide)Electronegativity Pauling scale: 1.1 Ionization energies 1st: 499 kJ/mol 2nd: 1170 kJ/mol 3rd: 1900 kJ/mol (more ) Covalent radius 215 pm Spectral lines of actiniumNatural occurrence from decay Crystal structure face-centered cubic (fcc)Thermal conductivity 12 W/(m⋅K) CAS Number 7440-34-8 Discovery and first isolationFriedrich Oskar Giesel (1902)Named by André-Louis Debierne (1899)
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Actinium is a silver radioactive , solid metal in actinide group. It is so radioactive that it glows in the dark. Even a small amount of actinium is dangerous to people.