Element 92 · Actinide
Uranium (U) — Element 92
Planet Uranus
Uranium (U) is an actinide in Period 7 (f-block) of the periodic table with atomic number 92, standard atomic weight 238.03 u, and ground-state electron configuration [Rn] 5f³ 6d¹ 7s². At standard temperature and pressure it is classified as a solid with 6 valence electrons and common oxidation states +6, +4.
Nuclear fuel, armor, dating
What are the atomic properties and physical constants of Uranium?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 92
- Standard atomic mass
- 238.03 u
- Chemical family
- Actinide
- Ground-state configuration
- [Rn] 5f³ 6d¹ 7s²
- Electrons per shell
- 2, 8, 18, 32, 21, 9, 2
- Valence electrons
- 6
- Common ion charges / oxidation states
- +6, +4
- Phase at STP
- Solid
- Pauling electronegativity
- 1.38 Pauling
- First ionization energy
- 598 kJ/mol
- Atomic radius
- —
- Melting point
- 1,132 °C
- Boiling point
- 4,131 °C
- Discovery year
- 1789
- Table coordinate
- Period 7, f-block
- Radioactivity
- Radioactive (no stable isotopes)
How are electrons arranged across Uranium’s shells?
A neutral Uranium atom contains 92 electrons distributed across 7 occupied principal energy shells ([Rn] 5f³ 6d¹ 7s²). The table below compares Uranium’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in U | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 18 e⁻ | 18 e⁻ |
| n = 4 | N | 32 e⁻ | 32 e⁻ |
| n = 5 | O | 21 e⁻ | 50 e⁻ |
| n = 6 | P | 9 e⁻ | 72 e⁻ |
| n = 7 | Q | 2 e⁻ | 98 e⁻ |
Frequently Asked Questions about Uranium (U)
What is the atomic mass and atomic number of Uranium (U)?
Uranium (U) has atomic number Z = 92 (92 protons in its nucleus) and an IUPAC standard atomic weight of 238.03 u. It sits in Period 7 in the f-block and is classified as an actinide.
What is the ground-state electron configuration of Uranium?
The neutral ground-state electron configuration of Uranium (Z = 92) is [Rn] 5f³ 6d¹ 7s². Across its 7 occupied principal shells (n = 1 to n = 7), the electrons per shell are 2, 8, 18, 32, 21, 9, 2, with 6 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Uranium?
Uranium commonly forms +6, +4 oxidation states or ion charges in compounds. Its Pauling electronegativity is 1.38 and its first ionization energy is 598 kJ/mol.
When was Uranium discovered and what is it used for?
Uranium was discovered in 1789 (Planet Uranus). Nuclear fuel, armor, dating
How does Uranium compare to neighboring elements?
Other actinide elements: