75ReRhenium186.207 u
Rhenium (Re)
Rhenium is a transition metal with atomic number 75, in period 6 and group 7 of the periodic table. Its atomic mass is 186.207 u and its electron configuration is [Xe] 4f¹⁴ 5d⁵ 6s². Solid at 25 °C.
Key facts
| Atomic number | 75 |
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| Atomic mass | 186.207 u |
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| Category | Transition Metal |
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| Period | 6 |
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| Group | 7 |
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| Block | d |
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| Electron configuration | [Xe] 4f¹⁴ 5d⁵ 6s² |
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| Electrons per shell | 2, 8, 18, 32, 13, 2 |
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| Electronegativity (Pauling) | 1.9 |
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| Oxidation states | −3, −1, +1, +2, +3, +4, +5, +6, +7common in bold |
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| State at 25 °C | Solid |
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| Melting point | 3459 K3185.85 °C |
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| Boiling point | 5869 K5595.85 °C |
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| Density | 20.8 g/cm³ |
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Atomic properties
| First ionization energy | 7.834 eV |
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| Electron affinity | 14.5 kJ/mol |
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| Atomic radius | 137 pm |
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| Covalent radius | 151 pm |
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| Van der Waals radius | 217 pm |
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| Common ions | Re⁷⁺ |
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| Protons, neutrons, electrons | 75, 111, 75 |
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Physical and thermal properties
| Molar volume | 8.86 cm³/mol |
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| Heat of fusion | 33 kJ/mol |
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| Heat of vaporization | 705 kJ/mol |
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| Specific heat | 137 J/(kg·K) |
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| Thermal conductivity | 48 W/(m·K) |
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| Thermal expansion | 6.2 × 10⁻⁶ K⁻¹ |
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| Mohs hardness | 7 |
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| Young’s modulus | 463 GPa |
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| Crystal structure | Simple hexagonal |
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| Magnetic type | Paramagnetic |
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Identification and history
| CAS number | 7440-15-5 |
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| Latin name | Rhenium |
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| Discovered by | W. Noddack, I. Tacke, O. Berg · 1925 |
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| Named by | W. & I. Noddack, O. Berg · 1925 |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 185Re | 184.952958 | 37.4 % |
| 187Re | 186.955752 | 62.6 % |
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.
See Rhenium in the app
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Periodic Table