Search results
Results from the WOW.Com Content Network
[13] [14] (The f-electron count for thorium metal is a non-integer due to a 5f–6d overlap.) [14] Among the actinides up to californium, which can be studied in at least milligram quantities, thorium has the highest melting and boiling points and second-lowest density; only actinium is lighter. Thorium's boiling point of 4788 °C is the fifth ...
In air, thorium burns to form the binary oxide thorium dioxide, ThO 2, also called thoria or thorina. [20] Thoria, a refractory material, has the highest melting point (3390 °C) of all known oxides. [21]
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] All thorium compounds, including the dioxide, are radioactive because there are no stable isotopes of thorium.
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. [38]: 2 Thorium is a fertile material, rather than a fissile one. This means that the fuel must be used in ...
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.
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 ...
It is covalently bound with low melting point of 55 °C. [2] The pentahydrate Th(NO 3) 4 •5H 2 O crystallizes with clear colourless crystals [6] in the orthorhombic system. The unit cell size is a=11.191 b=22.889 c=10.579 Å. Each thorium atom is connected twice to each of four bidentate nitrate groups, and to three water molecules via their ...
Thorium(IV) chloride can be produced in a variety of ways. One method is a carbothermic reaction, 700 °C to 2600 °C, involving thorium oxides and carbon in a stream of chlorine gas: ThO 2 + 2 C + 4 Cl 2 → ThCl 4 + 2 CO. The chlorination reaction can be effected with carbon tetrachloride: [3] [4] Th(C 2 O 4) 2 + CCl 4 → ThCl 4 + 3 CO + 3 CO 2