094Actinide · Group 3 · Period 7
Plutonium
Plutonium (Pu) is element 94, a actinide in the f-block — group 3, period 7. It is a solid at room temperature with 7 electron shells (2, 8, 18, 32, 24, 8, 2) and an atomic mass of 244 u.
- Atomic mass
- 244.0 u
- Phase · STP
- solid
- Melting
- 913 K · 639 °C
- Boiling
- 3505 K · 3232 °C
- Electronegativity
- 1.28
- Density
- 19.816 g/cm³
Photograph — Los Alamos National Laboratory, Attribution, via Wikimedia Commons
Identity
- Atomic number
- 94
- Standard atomic weight
- 244.0 u
- Category
- Actinide
- Group
- 3
- Period
- 7
- Block
- f-block
- Oxidation states
- +6, +5, +4, +3
Physical properties
- Melting point
- 913 K · 639 °C
- Boiling point
- 3505 K · 3232 °C
- Density
- 19.816 g/cm³
- Molar heat capacity
- 35.5 J/(mol·K)
- Atomic radius
- 243 pm
- Electron affinity
- -48.33 kJ/mol
Atomic structure
94protons
150neutrons
94electrons
2valence e⁻
- Noble-gas notation
- [Rn] 5f6 7s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f6
- Electrons per shell
- 2, 8, 18, 32, 24, 8, 2
Periodic trends
Where Plutonium ranks across all 118 elements.
Discovery
- Discovered
- 1940
- Discovered by
- Glenn T. Seaborg
- Named by
- —
- Appearance
- silvery white, tarnishing to dark gray in air