Periodic TablePlutonium (Pu)
Plutonium is an actinide with atomic number 94, in period 7, in the f-block of the periodic table. Its atomic mass is 244 u and its electron configuration is [Rn] 5f⁶ 7s². Solid at 25 °C.
Key facts
| Atomic number | 94 |
|---|---|
| Atomic mass | 244 u |
| Category | Actinide |
| Period | 7 |
| Group | f-block, no group number |
| Block | f |
| Electron configuration | [Rn] 5f⁶ 7s² |
| Electrons per shell | 2, 8, 18, 32, 24, 8, 2 |
| Electronegativity (Pauling) | 1.28 |
| Oxidation states | +2, +3, +4, +5, +6, +7common in bold |
| State at 25 °C | Solid |
| Melting point | 913 K639.85 °C |
| Boiling point | 3503 K3229.85 °C |
| Density | 19.816 g/cm³ |
Atomic properties
| First ionization energy | 6.026 eV |
|---|---|
| Electron affinity | --- |
| Atomic radius | 162 pm |
| Covalent radius | 187 pm |
| Van der Waals radius | 243 pm |
| Common ions | Pu⁴⁺, Pu⁶⁺ |
| Protons, neutrons, electrons | 94, 150, 94 |
Physical and thermal properties
| Molar volume | 12.29 cm³/mol |
|---|---|
| Heat of fusion | 2.82 kJ/mol |
| Heat of vaporization | 325 kJ/mol |
| Specific heat | 145 J/(kg·K) |
| Thermal conductivity | 6 W/(m·K) |
| Thermal expansion | --- |
| Mohs hardness | --- |
| Young’s modulus | 96 GPa |
| Crystal structure | Simple monoclinic |
| Magnetic type | Paramagnetic |
Identification and history
| CAS number | 7440-07-5 |
|---|---|
| Latin name | Plutonium |
| Discovered by | Glenn T. Seaborg · 1940 |
| Named by | --- |
Natural isotopes
Plutonium has no stable isotopes: every isotope is radioactive.
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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