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The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system. The melting point of thorium oxide is 3300 °C – the highest of all known oxides. Only a few elements (including tungsten and carbon) and a few compounds (including tantalum carbide) have higher melting points. [6]
As quoted in an online version of: David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition.CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Physical Properties of the Rare Earth Metals
Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely ...
Thorium was also used in certain glass elements of Aero-Ektar lenses made by Kodak during World War II. Thus they are mildly radioactive. [15] Two of the glass elements in the f/2.5 Aero-Ektar lenses are 11% and 13% thorium by weight. The thorium-containing glasses were used because they have a high refractive index with a low dispersion ...
For example, thorium perchlorate is very water-soluble and crystallises from acidic solutions as the tetrahydrate Th(ClO 4) 4 •4H 2 O, while thorium nitrate forms tetra- and pentahydrates, is soluble in water and alcohols, and is an important intermediate in the purification of thorium and its compounds. [25]
For example, the melting point of silicon at ambient pressure (0.1 MPa) is 1415 °C, but at pressures in excess of 10 GPa it decreases to 1000 °C. [13] Melting points are often used to characterize organic and inorganic compounds and to ascertain their purity. The melting point of a pure substance is always higher and has a smaller range than ...
The melting point of thorium dioxide (3350 °C) is greater than that of uranium dioxide (2800 °C), resulting in a need for increased sintering temperature or addition of non-reactive sintering aids to produce thorium dioxide-based fuel. [48]: 2 Thorium is a fertile material, rather than a fissile one. This means that the fuel must be used in ...