92 · U
Uranium
Oxide identified by Klaproth in 1789. Metal isolated by Péligot in 1841.
Identity
- Atomic number
- 92
- Symbol
- U
- Canonical name
- Uranium
- Category
- actinide
- Group
- unassigned
- Period
- 7
- Block
- f
Series set apart from the main table. Whether group 3 is lanthanum or lutetium (actinium or lawrencium) is still discussed, so the group is left empty.
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- 238.028913 u
- Electron configuration
- [Rn] 5f3 6d1 7s2
- Electrons per shell
- 2, 8, 18, 32, 21, 9, 2
- Standard state
- solid
- Density
- 19.1 g/cm³
- Melting point
- 1,405.3 K
- Boiling point
- 4,404 K
- Electronegativity
- 1.38 Pauling
- First ionization energy
- 597.6 kJ/mol
- Electron affinity
- 50.94 kJ/mol
Notable isotopes
This summary is not an inventory of every isotope.
- U-238 · 99.27 % · primordial · 4,468,000,000 years · alpha
- U-235 · 0.72 % · primordial · 704,000,000 years · alpha
History
An oxide taken for the metal
Identification · confirmed · 1789
Klaproth identifies a new element in pitchblende. The body he obtains is still an oxide.
Metal isolated
Isolation · confirmed · 1841
Péligot isolates uranium metal and shows that Klaproth’s product was not the metal.
Etymology
- Theme
- celestial body
- Language
- grec
- Root
- Ouranos
- Meaning
- Uranus
Scientists
Places and institutions
- Berlin — historical setting : Prussia, then Germany — present country : Germany
- Paris — historical setting : France — present country : France
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements