Plutonium (Pu)
Plutonium (Pu) is element 94, an actinide. Atomic mass 244, configuration [Rn] 5f⁶ 7s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 94 |
|---|---|
| Symbol | Pu |
| Standard atomic weight | 244 |
| Category | Actinide |
| Period | 7 |
| State at room temperature | Solid |
| Electron configuration | [Rn] 5f⁶ 7s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +4 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.3 |
| First ionization energy | 585 kJ/mol |
| Atomic radius | 175 pm |
| Density | 19.7 g/cm³ |
| Melting point | 640°C |
| Boiling point | 3228°C |
Common uses
- Nuclear weapons
- RTG power for spacecraft (Voyager/Mars rovers)
Where it matters
- Global Security (Nuclear non-proliferation)
- Space Exploration (RTG batteries)
Hazards
- Extremely radiotoxic
- criticality hazard
History
| Discovered | 1940 |
|---|---|
| Discovered by | Seaborg, McMillan, Kennedy, Wahl |
| Name | Planet Pluto |