58CeCerium140.116 u
Cerium (Ce)
Cerium is a lanthanide with atomic number 58, in period 6, in the f-block of the periodic table. Its atomic mass is 140.116 u and its electron configuration is [Xe] 4f¹ 5d¹ 6s². Solid at 25 °C.
Key facts
| Atomic number | 58 |
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| Atomic mass | 140.116 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] 4f¹ 5d¹ 6s² |
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| Electrons per shell | 2, 8, 18, 19, 9, 2 |
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| Electronegativity (Pauling) | 1.12 |
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| Oxidation states | +2, +3, +4common in bold |
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| State at 25 °C | Solid |
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| Melting point | 1071 K797.85 °C |
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| Boiling point | 3697 K3423.85 °C |
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| Density | 6.77 g/cm³ |
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Atomic properties
| First ionization energy | 5.539 eV |
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| Electron affinity | 50 kJ/mol |
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| Atomic radius | 181 pm |
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| Covalent radius | 204 pm |
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| Van der Waals radius | 235 pm |
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| Common ions | Ce³⁺ |
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| Protons, neutrons, electrons | 58, 82, 58 |
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Physical and thermal properties
| Molar volume | 20.69 cm³/mol |
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| Heat of fusion | 5.5 kJ/mol |
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| Heat of vaporization | 350 kJ/mol |
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| Specific heat | 192 J/(kg·K) |
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| Thermal conductivity | 11 W/(m·K) |
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| Thermal expansion | 6.3 × 10⁻⁶ K⁻¹ |
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| Mohs hardness | 2.5 |
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| Young’s modulus | 34 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 | 7440-45-1 |
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| Latin name | Cerium |
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| Discovered by | Klaproth, Berzelius, Hisinger · 1803 |
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| Named by | --- |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 136Ce | 135.907129 | 0.186 % |
| 138Ce | 137.905994 | 0.251 % |
| 140Ce | 139.905448 | 88.449 % |
| 142Ce | 141.90925 | 11.114 % |
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 Cerium in the app
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Periodic Table