Atomic number:92

Group numbers:3

Period:7

Electronic configuration:[Rn] 5f³ 6d¹ 7s²

Formal oxidation number:+3 +4 +5 +6

Electronegativities:1.7

Atomic radius / pm:138.5

Relative atomic mass:238.02891 ± 0.00003

 

Uranium was discovered by Martin Heinrich Klaproth (DE) in 1789. Named after the planet Uranus. It is a silvery-white, dense, ductile, malleable, radioactive, radiotoxic metal that resists alkalis, tarnishes in air and reacts with steam and acids. Uranium occurs in many rocks, but in large amounts only in such minerals as pitchblende and carnotite. For many centuries it was used as a pigment for glass. Now it is used as a fuel in nuclear reactors and in bombs.

Density / g dm^-3:18950 (293 K)

 17907 (m.p.)

Molar volume / cm³mol^-1:12.56 (293 K)

 13.29 (m.p.)

Electrical resistivity / μΩcm:30 (20 °C)

Thermal conductivity / W m^-1K^-1:27.6

Melting point / °C:1135

Boiling point / °C:4131

Heat of fusion / kJ mol^-1:15.5

Heat of vaporization / kJ mol^-1:417.1

Heat of atomization / kJ mol^-1:535.43

1st ionization energy / kJ mol^-1:597.64

2nd ionization energy / kJ mol^-1:-

3rd ionization energy / kJ mol^-1:-

in the atmosphere / ppm:-

in the Earth's crust / ppm:0.91

in the oceans / ppm:0.003