Uranium

Atomic number

92

Atomic mass (u)

238.0289

Category

Actinide

Standard state

Solid

Melting point

1134.85 °C (1408 K)

Boiling point

4130.85 °C (4404 K)

Density (g/cm³)

18.95

Electronegativity (Pauling)

1.38

Electron configuration

[Rn]7s2 5f3 6d1

Oxidation states

+6, +5, +4, +3

Atomic radius (pm)

240

First ionization energy (eV)

6.194

Discovery & recognition

Discovery year / period (PubChem)

1789

Discovery credited to (RSC)

Martin Heinrich Klaproth

Date or period recorded by RSC

1789

Discovery place

Not supplied in the structured record; see the RSC history source.

An ancient date does not identify a first human discovery. Different references may date observation, isolation and formal recognition differently.

Natural occurrence & production

The creation of an element’s nuclei and its concentration into terrestrial deposits are different processes. The occurrence note below concerns its presence or production on Earth; it is not a complete account of nucleosynthesis.

“Uranium occurs naturally in several minerals such as uranite (pitchblende), brannerite and carnotite.”

Royal Society of Chemistry · occurrence excerpt ↗

Continue the research

Reference values are not product specifications. Blank values have not been estimated. For superheavy elements, some properties and family assignments are theoretical or incompletely measured.