| Compound | Thorium |
| Synonyms | |
| Formula | Th |
| Molecular Formula | Th |
| Molecular Weight | 232.0381 |
| CAS RN: | 7440-29-1 |
| Properties | soft; grayish white, lustrous metal; somewhat ductile; α: fcc up to 1400°C, a=0.5086 mm; β:bcc, a=0.411 nm, stable 1400 to 1750°C; enthalpy of vaporization 564 kJ/mol; enthalpy of fusion 13.81 kJ/mol; electrical resistivity 14 mohmm·cm; Poisson’s ratio 0.27; thermal diffusivity 0.28 cm²/s at 200°C, t½ ²³²Th is 1.41 x 10+¹º years; ionic radious of Th++++ is 0.0972 nm [KIR78] [KIR83] [MER89] [CRC93] |
| Solubility | s acids; i H2O, alkalies [HAW93] |
| Density, g/cm³: | α: 11.724 [KIR91] |
| Melting point, °C | 1750 [KIR91] |
| Boiling point, °C | 3800 [ALD94] |
| Reactions: | phase change from fcc to bcc ~1345°C [KIR83] |
| Thermal Conductivity, W/(m·K) | 54.0 (25°C) [CRC93] |
| Thermal Expansion Coefficient | 11.0 x 10 ˉ6/K [CRC93] |