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Thorium oxide gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eye glasses.
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Thorium and oxide
Thorium is also used in its oxide form ( thoria ) in gas tungsten arc welding ( GTAW ) to increase the high-temperature strength of tungsten electrodes and improve arc stability.
Thorium oxide has very low emissivity in the near infrared region than the shorter wavelength parts of the visible spectrum.
Thorium and high
Thorium is dimorphic, changing at 1360 ° C from a face-centered cubic to a body-centered cubic structure ; a body-centered tetragonal lattice form exists at high pressure with impurities driving the exact transition temperatures and pressures.
Thorium is a component of the magnesium alloy series, called Mag-Thor, used in aircraft engines and rockets and imparting high strength and creep resistance at elevated temperatures.
Thorium compounds produce excellent images because of thorium's high opacity to X-rays ( it has a high cross section for absorption ).
Thorium and low
Thorium is added because of its ability to emit electrons at relatively low temperatures when heated in vacuum.
Thorium and was
Thorium and uranium are the two most common radioactive elements on earth ; they have been around since the earth was formed.
Thorium was once commonly used as the light source in gas mantles and as an alloying material, but these applications have declined due to concerns about its radioactivity.
Thorium dioxide was used to control the grain size of tungsten metal used for spirals of electric lamps.
Thorium fluoride was also used in manufacturing carbon arc lamps, which provided high-intensity illumination for movie projectors and search lights.
Thorium was removed by taking advantage of its weaker basicity relative to the trivalent lanthanides, the radioactive radium isotope daughter products of thorium were precipitated out using entrainment in barium sulfate, and the remaining lanthanides were converted to the chloride.
* Thorium: Radioactivity was unknown at that time, and the dentist probably thought he was working with tin.
Its final core was an experimental, light water moderated, thermal breeder reactor and is notable for its ability to transmute ( inexpensive ) Thorium 232 to Uranium 233 ( the latter being the fissile material that fueled the reaction within the reactor core ).
Thorium and used
Thorium is also used as an alloying element in nonconsumable TIG welding electrodes.
Thorium is a very effective radiation shield, although it has not been used for this purpose as much as lead or depleted uranium.
Thorium dioxide ( ThO < sub > 2 </ sub >) and thorium nitrate () were used in mantles of portable gas lights, including natural gas lamps, oil lamps and camping lights.
Thorium dioxide has been used as a catalyst in the conversion of ammonia to nitric acid, in petroleum cracking and in producing sulfuric acid.
Thorium and plutonium fluorides have also been used.
Uranium-233 has been used as a fuel in several different reactor types, and is proposed as a fuel for several new designs ( see Thorium fuel cycle ).
Thorium and due
Natural gamma-ray tools are designed to measure naturally occurring gamma radiation in the earth caused by the disintegration due to Potassium, Uranium, and Thorium.
Thorium and its
Thorium precipitates as its hydroxide and is removed.
Thorium and uranium, their decay product radium, and its decay product radon, will therefore continue to occur for tens of millions of years at almost the same concentrations as they do now.
Thorium is radioactive and produces a radioactive gas, radon-220, as one of its decay products.
: India refused to accept any American imposed limits on its trade and went ahead with shipments of Thorium nitrate to China.
Thorium and has
Thorium has one of the largest liquid temperature ranges of any element, with 2946 ° C between the melting point and boiling point.
Thorium dioxide has the highest melting point ( 3300 ° C ) of all oxides.
Thorium monoxide has recently been produced through laser ablation of thorium in the presence of oxygen.
Thorium dioxide is commonly a major component ; being radioactive it has led to concerns about the safety of those involved in manufacturing mantles.
Thorium and by
* The Industrial Chemistry of the Lanthanons, Yttrium, Thorium and Uranium, by R. J. Callow, Pergamon Press 1967
*" The Industrial Chemistry of the Lanthanons, Yttrium, Thorium and Uranium ", by R. J. Callow, Pergamon Press 1967.
Thorium is slowly attacked by water, but does not dissolve readily in most common acids, except hydrochloric acid.
Thorium concentrations on the Moon, as mapped by Lunar Prospector.
" The Crystal Structure of Thorium and Zirconium Dihydrides by X-ray and Neutron Diffraction ", Ames Laboratory, Oak Ridge National Laboratory ( ORNL ), United States Department of Energy ( through predecessor agency the Atomic Energy Commission ), ( Apr.
In a fast breeder reactor, the above applies, though the reactivity from fuel depletion is also compensated by the breeding of either Uranium-233 or Plutonium-239 and 241 from Thorium 232 or Uranium 238, respectively.
* Langmuir, Irving ; and Kingdon, Kenneth H .; The Removal of Thorium from the Surface of a Thoriated Tungsten Filament by Positive Ion Bombardment, Physical Review, Vol.
Thorium and .
Thorium occurs in all granites as well.
Thorium precipitates out of solution as hydroxide and is removed.
* Thorium based reactors.
The island is rich with minerals such as Ilmenite, Feldspar, Graphite, Silica, Kaolin, Mica and Thorium.
Thorium ( ) is a naturally occurring radioactive chemical element with the symbol Th and atomic number 90.
Thorium is estimated to be about four times more abundant than uranium in the Earth's crust, and is chiefly refined from monazite sands as a by-product of extracting rare earth metals.
Thorium compounds are stable in the + 4 oxidation state.
Thorium ( IV ) nitrate and thorium ( IV ) fluoride are known in their hydrated forms: and, respectively.
Thorium ( IV ) carbonate,, is also known.
Thorium ( IV ) hydroxide,, is highly insoluble in water, and is not amphoteric.
0.155 seconds.