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Actinium, 89AcFile:Actinium sample (31481701837).png |
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Pronunciation | (ak-TIN-ee-əm) |
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Appearance | silvery-white, glowing with an eerie blue light;[1] sometimes with a golden cast[2] |
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Mass number | [227] |
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Atomic number (Z) | 89 |
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Group | f-block groups (no number) |
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Period | period 7 |
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Block | f-block |
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Electron configuration | [Rn] 6d1 7s2 |
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Electrons per shell | 2, 8, 18, 32, 18, 9, 2 |
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Phase at STP | solid |
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Melting point | 1500 K (1227 °C, 2240 °F) (estimated)[2] |
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Boiling point | 3500±300 K (3200±300 °C, 5800±500 °F) (extrapolated)[2] |
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Density (near r.t.) | 10 g/cm3 |
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Heat of fusion | 14 kJ/mol |
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Heat of vaporization | 400 kJ/mol |
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Molar heat capacity | 27.2 J/(mol·K) |
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Oxidation states | common: +3
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Electronegativity | Pauling scale: 1.1 |
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Ionization energies | - 1st: 499 kJ/mol
- 2nd: 1170 kJ/mol
- 3rd: 1900 kJ/mol
- (more)
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Covalent radius | 215 pm |
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Color lines in a spectral rangeSpectral lines of actinium |
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Natural occurrence | from decay |
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Crystal structure | face-centered cubic (fcc) (cF4) |
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Lattice constant | a = 531.5 pm (at 20 °C)[3] |
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Thermal conductivity | 12 W/(m⋅K) |
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CAS Number | 7440-34-8 |
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Discovery | Friedrich Oskar Giesel (1902) |
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First isolation | Joseph G. Stites, Murrell L. Salutsky, Bob D. Stone (1955) |
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Named by | André-Louis Debierne (1899) |
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File:Symbol category class.svg Category: Actinium | references |
child table, as reused in {IB-Ac} |
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References
These references will appear in the article, but this list appears only on this page.
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- ↑ Lua error in Module:Citation/CS1/Configuration at line 2088: attempt to index field '?' (a nil value).
- ↑ Jump up to: 4.0 4.1 Lua error in Module:Citation/CS1/Configuration at line 2088: attempt to index field '?' (a nil value).
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