Uranium

protactinium ← uranium → neptunium Nd ↑ U ↓ —

Atomic properties Atomic number 92 Standard atomic weight 238.028 91(3) Electron configuration [Rn] 5f3 6d1 7s2 Physical properties Melting point 1130 °C (1400 K) Boiling point 3930 °C (4200 K) Density 19.05 g cm−3 Electric resistivity 28 × 10−6 Ω cm Chemical properties Electronegativity 1.38 (Pauling) Ionization energy 6.19 eV, 597 kJ mol−1 Atomic radii Covalent radius 196 pm Metallic radius 156 pm Ionic radius 87 pm (U6+, Oh) 103 pm (U4+, Oh) Thermodynamic properties Standard entropy 50.20(20) J K−1 mol−1 Enthalpy change of atomization 533(8) kJ mol−1 Entropy change of atomization 149.59(22) J K−1 mol−1 Enthalpy change of fusion 12.6 kJ mol−1 Enthalpy change of vaporization 417 kJ mol−1 Hazards GHS pictograms GHS signal word DANGER GHS hazard statements H330, H300, H373, H413 Miscellaneous CAS number 7440-61-1 EC number 231-170-6 Where appropriate, and unless otherwise stated, data are given for 100 kPa (1 bar) and 298.15 K (25 °C).

Uranium (symbol: U) is a member of the actinoid series of chemical elements.

Notes and references

Further reading

• Grenthe, Ingmar; Drożdżyński, Janusz; Fujino, Takeo; Buck, Edgar C.; Albrecht-Schmitt, Thomas E.; Wolf, Stephen F. Uranium. In The Chemistry of the Actinide and Transactinide Elements, 3rd ed.; Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean, Eds.; Springer: Dordrecht, the Netherlands, 2006; Vol. 1, Chapter 5, pp 253–698. doi:10.1007/1-4020-3598-5_5, <http://radchem.nevada.edu/classes/rdch710/files/uranium.pdf>.

External links

• WebElements