| From Wikipedia, the free encyclopediaUranium is a chemical element with symbol U and atomic number 92. It is a silvery-white metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. | |||||||||
Uranium in the periodic table | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Symbol | U | ||||||||
| Atomic number | 92 | ||||||||
| Group | 0 | ||||||||
| Period | 7 | ||||||||
| Block | f | ||||||||
| Element category | Actinide | ||||||||
Physical properties | |||||||||
| Phase at STP | Solid | ||||||||
| Density | 19.1 g/cm3 | ||||||||
| Atomic weight | 238.029 u | ||||||||
| Melting point | 1405.3 K 1132.15 °C 2069.87 °F | ||||||||
| Boiling point | 4404 K 4130.85 °C 7467.53 °F | ||||||||
Atomic properties | |||||||||
| Electronegativity (Pauling Scale) | 1.38 | ||||||||
| Electron affinity | 50.94 kJ/mol | ||||||||
| Oxidation states | +1, +2, +3, +4, +5, +6 (an amphoteric oxide) | ||||||||
| Ionization energies |
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Electron configuration | |||||||||
| Elektronkonfiguration (shorthand) | [Rn] 5f3 6d1 7s2 | ||||||||
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f3 6s2 6p6 6d1 7s2 | ||||||||
| Electrons per shell | 2, 8, 18, 32, 21, 9, 2 | ||||||||
History | |||||||||
| Discovered | 1789 | ||||||||
| Discovered by | Martin Heinrich Klaproth | ||||||||