| Compound |
Uranium |
| Synonyms |
|
| Formula |
U |
| Molecular Formula |
U |
| Molecular Weight |
238.0289 |
| CAS RN: |
7440-61-1 |
| Properties |
silvery white, lustrous; black powder, when obtained by reduction of UF4; three forms, α-form: ortho-rhomb; a=0.2854 nm, b=0.5869 nm, c=0.4956 nm; β: tetr, a=1.0763 nm, c=0.5652 nm; γ:bcc, a=0.3524 nm; resistivity 29 mohm·cm; enthalpy of fusion 9.14 kJ/mol; enthalpy of sublimation 1062.73 kJ/mol; flammable in air forming U3O8; t½ 238U is4.47 x 10+9 years, ionic radius of U++++0.0918 nm [MER89] [KIR78] [KIR83] [CRC93] |
| Solubility |
|
| Density, g/cm3: |
α: 19.07; β: 18.11; γ: 18.06 [KIR83] |
| Melting point, C |
1132 [KIR91] |
| Boiling point, C |
3818 [ALD94] |
| Reactions: |
transition α to β at 667.7°C, β to γ at 774.8°C [MER89] |
| Thermal Conductivity, W/(m·K): |
25.1 (36°C), 26.3 (100°C), 29.7 (200°C), 31.4 (300°C), 32.6 (400°C) [KIR83] |