Element 92
Uranium (U)
Uranium (U) is element 92 of the periodic table, a actinide in period 7 (f-block) with an atomic mass of 238.03 and is a solid at standard conditions.
At a glance
- Atomic number
- 92
- Symbol
- U
- Atomic mass
- 238.03 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 5f3 6d1 7s2
- Shorthand configuration
- [Rn] 5f3 6d1 7s2
- Electrons per shell
- 2, 8, 18, 32, 21, 9, 2
- Oxidation states
- +1, +2, +3, +4, +5, +6
Physical properties
- Melting point
- 1405.3 K
- Boiling point
- 4404 K
- Density
- 18.95 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.38
- Atomic radius
- 156 pm
- Covalent radius
- 196 pm
- Van der Waals radius
- 186 pm
- First ionization energy
- 598 kJ/mol
- Electron affinity
- 51 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| U-238 | 238.05079 | — | Half-life 4.47 billion years |
Common uses
- Nuclear power
- Nuclear weapons
- Medical isotopes
- Dating rocks
Discovery
- Year
- 1789
- Discovered by
- Martin Heinrich Klaproth
- Country
- Germany