Uranium
The heaviest natural element, fuel for reactors and weapons.
Inside the Uranium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Uranium atom step by step.
Electron configuration
[Rn] 5f3 6d1 7s2
A neutral Uranium atom has 92 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 1405 K (1132 °C)
- Boiling point
- 4404 K (4131 °C)
- Density
- 18.95 g/cm³
- Electronegativity
- 1.38 Pauling
- Atomic radius
- 175 pm
- 1st ionization energy
- 598 kJ/mol
- Category
- Actinides
Discovery & naming
- Discovered
- 1789
- Discovered by
- Martin Heinrich Klaproth
- Origin of name
- The planet Uranus.
Notable uses
Nuclear reactor fuel and weapons.
Where Uranium comes from
Neutron star mergers
Requires rapid neutron capture. The uranium warming Earth's interior predates the Sun that Earth orbits.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 92
- Atomic mass
- 238.03
- Category
- Actinides
- Group · Period
- — · 7
- Block
- f-block
- Shells
- 2 · 8 · 18 · 32 · 21 · 9 · 2