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Pronunciation | (FRAN-see-əm) |
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Mass number | [223] |
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Group | group 1: hydrogen and alkali metals |
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Period | period 7 |
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Block | s-block |
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Electron configuration | [Rn] 7s1 |
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Electrons per shell | 2, 8, 18, 32, 18, 8, 1 |
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Phase at STP | solid presumably |
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Melting point | ? 300 K (27 °C, 80 °F) |
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Boiling point | ? 950 K (677 °C, 1250 °F) |
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Density (near r.t.) | 1.87 g/cm3 (extrapolated) |
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Heat of fusion | ca. 2 kJ/mol |
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Heat of vaporization | ca. 65 kJ/mol |
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Vapor pressure (extrapolated)
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
404 |
454 |
519 |
608 |
738 |
946 |
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Oxidation states | +1 (expected to have a strongly basic oxide) |
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Electronegativity | Pauling scale: 0.7 |
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Ionization energies | |
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Covalent radius | 260 pm (extrapolated) |
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Van der Waals radius | 348 pm (extrapolated) |
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Natural occurrence | from decay |
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Crystal structure | body-centered cubic (bcc) (extrapolated) |
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Thermal conductivity | 15 W/(m⋅K) (extrapolated) |
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Electrical resistivity | 3 µΩ⋅m (calculated) |
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Magnetic ordering | Paramagnetic |
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CAS Number | 7440-73-5 |
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Discovery | 1939 |
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Category: Francium | references |