Uranium (U) – element 92
Uranium is a chemical element with the symbol U and atomic number 92. It is a actinide in group 3 (actinides), period 7 of the periodic table (f-block), and is a solid at room temperature.
Uranium (U) has atomic number 92, atomic mass 238.03 u and electron configuration [Rn] 5f3 6d1 7s2.
Uranium facts
| Symbol | U |
|---|---|
| Atomic number | 92 |
| Atomic mass | 238.03 u (g/mol) |
| Category | actinide |
| Group | group 3 (actinides) |
| Period | 7 |
| Block | f-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f3 6d1 |
| Noble-gas notation | [Rn] 5f3 6d1 7s2 |
| Electrons per shell | 2, 8, 18, 32, 21, 9, 2 |
Bohr model and shells
Uranium has 92 electrons in 7 shells: 2, 8, 18, 32, 21, 9, 2. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.
Physical and atomic properties
| Melting point | 1405.3 K (1132.2 °C) |
|---|---|
| Boiling point | 4404 K (4130.9 °C) |
| Density | 19.1 g/cm³ |
| Electronegativity (Pauling) | 1.38 |
| Electron affinity | 50.94 kJ/mol |
| Ionization energies | 597.6, 1420 kJ/mol (1st, 2nd) |
| Molar heat capacity | 27.665 J/(mol·K) |
| Discovered by | Martin Heinrich Klaproth |
Use the atomic mass in the molar mass calculator for any formula containing U.
Position in the periodic table
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Frequently asked questions
What is the atomic mass of uranium?
The atomic mass of uranium is 238.03 u, so one mole of uranium atoms weighs 238.03 g.
What is the electron configuration of uranium?
Uranium has 92 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f³ 6d¹, or [Rn] 5f³ 6d¹ 7s² in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 21, 9, 2.
Is uranium a metal?
Yes. Uranium is a actinide.
Where is uranium on the periodic table?
Uranium is in group 3 (actinides), period 7, in the f-block.
Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.