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Francium, 87Fr|
Pronunciation | (FRAN-see-əm) |
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Mass number | [223] |
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Atomic number (Z) | 87 |
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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 |
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Melting point | 300 K (27 °C, 81 °F) |
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Boiling point | 950 K (677 °C, 1251 °F) |
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Density (near r.t.) | 2.458 g/cm3 (estimated)[1] |
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Vapor pressure (extrapolated)
P (Pa)
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1
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10
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100
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1 k
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10 k
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100 k
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at T (K)
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404
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454
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519
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608
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738
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946
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Oxidation states | common: +1
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Electronegativity | Pauling scale: >0.79 |
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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)[1] |
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Lattice constant | a = 670.4 pm (estimated)[1] |
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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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Naming | after France, homeland of the discoverer |
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Discovery and first isolation | Marguerite Perey (1939) |
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File:Symbol category class.svg Category: Francium | references |
child table, as reused in {IB-Fr} |
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References
These references will appear in the article, but this list appears only on this page.
- ↑ 1.0 1.1 1.2 Lua error in Module:Citation/CS1/Configuration at line 2088: attempt to index field '?' (a nil value).
- ↑ ISOLDE Collaboration, J. Phys. B 23, 3511 (1990) (PDF online)
- ↑ 3.0 3.1 Lua error in Module:Citation/CS1/Configuration at line 2088: attempt to index field '?' (a nil value).
Lua error in mw.title.lua at line 230: too many expensive function calls.