64GdGadolinium157.25 u
Gadolinium (Gd)
Gadolinium is a lanthanide with atomic number 64, in period 6, in the f-block of the periodic table. Its atomic mass is 157.25 u and its electron configuration is [Xe] 4f⁷ 5d¹ 6s². Solid at 25 °C.
Key facts
| Atomic number | 64 |
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| Atomic mass | 157.25 u |
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| Category | Lanthanide |
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| Period | 6 |
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| Group | f-block, no group number |
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| Block | f |
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| Electron configuration | [Xe] 4f⁷ 5d¹ 6s² |
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| Electrons per shell | 2, 8, 18, 25, 9, 2 |
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| Electronegativity (Pauling) | 1.2 |
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| Oxidation states | +1, +2, +3common in bold |
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| State at 25 °C | Solid |
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| Melting point | 1586 K1312.85 °C |
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| Boiling point | 3546 K3272.85 °C |
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| Density | 7.901 g/cm³ |
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Atomic properties
| First ionization energy | 6.15 eV |
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| Electron affinity | 50 kJ/mol |
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| Atomic radius | 179 pm |
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| Covalent radius | 196 pm |
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| Van der Waals radius | 237 pm |
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| Common ions | Gd³⁺ |
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| Protons, neutrons, electrons | 64, 93, 64 |
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Physical and thermal properties
| Molar volume | 19.9 cm³/mol |
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| Heat of fusion | 10 kJ/mol |
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| Heat of vaporization | 305 kJ/mol |
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| Specific heat | 240 J/(kg·K) |
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| Thermal conductivity | 11 W/(m·K) |
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| Thermal expansion | 9.4 × 10⁻⁶ K⁻¹ |
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| Mohs hardness | 5.13 |
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| Young’s modulus | 55 GPa |
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| Crystal structure | Simple hexagonal |
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| Magnetic type | Ferromagnetic |
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Identification and history
| CAS number | 7440-54-2 |
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| Latin name | Gadolinium |
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| Discovered by | Jean Ch. Galissard de Marignac · 1880 |
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| Named by | --- |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 152Gd | 151.919798 | 0.2 % |
| 154Gd | 153.920873 | 2.18 % |
| 155Gd | 154.922629 | 14.8 % |
| 156Gd | 155.92213 | 20.47 % |
| 157Gd | 156.923967 | 15.65 % |
| 158Gd | 157.924111 | 24.84 % |
| 160Gd | 159.927061 | 21.86 % |
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