Periodic table / Actinoids

92Uranium

Uranium is an actinoid in period 7, in the actinoid series. At 25 °C it is a solid.

U
Shells: 2, 8, 18, 32, 21, 9, 2. A simple picture: electrons do not move in circles.
Symbol
U
Atomic number
92 protons in the nucleus
Standard atomic weight
238.03 ± 0.01
Electron configuration
[Rn] 5f3 6d1 7s2
Electrons in each shell
2, 8, 18, 32, 21, 9, 2
Group, period, block
–, 7, f
Family
Actinoids
State at 25 °C
solid
Electronegativity
1.38 (Pauling scale)
First ionisation energy
597.6 kJ/mol (6.19405 eV)
Where these numbers come from

Atomic weight: IUPAC CIAAW, abridged standard atomic weights 2024. Electron configuration and ionisation energy: NIST Atomic Spectra Database. Family, state and electronegativity: PubChem. See Sources. Melting points, boiling points and densities are left out for now: published values differ between sources, and we will add them once each has been checked.