83BiBismuth208.9804 u
Bismuth (Bi)
Bismuth is a post-transition metal with atomic number 83, in period 6 and group 15 of the periodic table. Its atomic mass is 208.9804 u and its electron configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³. Solid at 25 °C.
Key facts
| Atomic number | 83 |
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| Atomic mass | 208.9804 u |
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| Category | Post-Transition Metal |
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| Period | 6 |
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| Group | 15 |
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| Block | p |
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| Electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³ |
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| Electrons per shell | 2, 8, 18, 32, 18, 5 |
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| Electronegativity (Pauling) | 2.02 |
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| Oxidation states | −3, −2, −1, +1, +2, +3, +4, +5common in bold |
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| State at 25 °C | Solid |
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| Melting point | 544.4 K271.25 °C |
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| Boiling point | 1837 K1563.85 °C |
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| Density | 9.78 g/cm³ |
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Atomic properties
| First ionization energy | 7.286 eV |
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| Electron affinity | 91.2 kJ/mol |
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| Atomic radius | 170 pm |
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| Covalent radius | 148 pm |
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| Van der Waals radius | 207 pm |
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| Common ions | Bi³⁺, Bi⁵⁺ |
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| Protons, neutrons, electrons | 83, 126, 83 |
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Physical and thermal properties
| Molar volume | 21.31 cm³/mol |
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| Heat of fusion | 10.9 kJ/mol |
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| Heat of vaporization | 160 kJ/mol |
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| Specific heat | 122 J/(kg·K) |
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| Thermal conductivity | 8 W/(m·K) |
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| Thermal expansion | 1.34 × 10⁻⁵ K⁻¹ |
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| Mohs hardness | 2.25 |
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| Young’s modulus | 32 GPa |
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| Crystal structure | Base-centered monoclinic |
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| Magnetic type | Diamagnetic |
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Identification and history
| CAS number | 7440-69-9 |
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| Latin name | Bisemutum |
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| Discovered by | Claude François Geoffroy · 1753 |
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| Named by | --- |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 209Bi | 208.980399 | 100 % |
Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.
A dash (---) means there is no reliable published measurement. The app never makes one up.
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Periodic Table