Element 94
Plutonium (Pu)
Plutonium (Pu) is element 94 of the periodic table, a actinide in period 7 (f-block) with an atomic mass of 244 and is a solid at standard conditions.
At a glance
- Atomic number
- 94
- Symbol
- Pu
- Atomic mass
- 244 u
- Category
- Actinides
- Period
- 7
- Block
- f-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f6 7s2
- Shorthand configuration
- [Rn] 5f6 7s2
- Electrons per shell
- 2, 8, 18, 32, 24, 8, 2
- Oxidation states
- +2, +3, +4, +5, +6, +7, +8
Physical properties
- Melting point
- 912.5 K
- Boiling point
- 3501 K
- Density
- 19.84 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.28
- Atomic radius
- 159 pm
- Covalent radius
- 187 pm
- First ionization energy
- 585 kJ/mol
- Electron affinity
- 53 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Pu-244 | 244.0642 | — | Half-life 80.8 million years |
Common uses
- Nuclear weapons
- Nuclear power
- Spacecraft power
Discovery
- Year
- 1940
- Discovered by
- Glenn T. Seaborg, Edwin McMillan, Joseph W. Kennedy, Arthur Wahl
- Country
- USA