Difference between revisions of "Thorium"
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| + | {{Infobox element | ||
| + | <!-- top --> | ||
| + | |image name= | ||
| + | |image alt= | ||
| + | |image size= | ||
| + | |image name comment= | ||
| + | |image name 2= | ||
| + | |image alt 2= | ||
| + | |image size 2= | ||
| + | |image name 2 comment= | ||
| + | <!-- General properties --> | ||
| + | |name=Thorium | ||
| + | |symbol=Th | ||
| + | |pronounce= | ||
| + | |pronounce ref= | ||
| + | |pronounce comment= | ||
| + | |pronounce 2= | ||
| + | |alt name= | ||
| + | |alt names= | ||
| + | |allotropes= | ||
| + | |appearance=Silvery-grey, often black tarnish | ||
| + | <!-- Periodic table --> | ||
| + | |above=[[Cerium|Ce]] | ||
| + | |below=Uqq | ||
| + | |left=[[Actinium]] | ||
| + | |right=[[Protactinium]] | ||
| + | |number=90 | ||
| + | |atomic mass=232.0377(4) | ||
| + | |atomic mass 2= | ||
| + | |atomic mass ref= | ||
| + | |atomic mass comment= | ||
| + | |series= | ||
| + | |series ref= | ||
| + | |series comment=Actinides | ||
| + | |series color= | ||
| + | |group= | ||
| + | |group ref= | ||
| + | |group comment=n/a | ||
| + | |period=7 | ||
| + | |period ref= | ||
| + | |period comment= | ||
| + | |block=f | ||
| + | |block ref= | ||
| + | |block comment= | ||
| + | |electron configuration=[Rn] 6d<sup>2</sup> 7s<sup>2</sup> | ||
| + | |electron configuration ref= | ||
| + | |electron configuration comment= | ||
| + | |electrons per shell=2, 8, 18, 32, 18, 10, 2 | ||
| + | |electrons per shell ref= | ||
| + | |electrons per shell comment= | ||
| + | <!-- Physical properties --> | ||
| + | |physical properties comment= | ||
| + | |color=Silvery-gray | ||
| + | |phase=Solid | ||
| + | |phase ref= | ||
| + | |phase comment= | ||
| + | |melting point K=2023 | ||
| + | |melting point C=1750 | ||
| + | |melting point F=3182 | ||
| + | |melting point ref= | ||
| + | |melting point comment= | ||
| + | |boiling point K=5061 | ||
| + | |boiling point C=4788 | ||
| + | |boiling point F=8650 | ||
| + | |boiling point ref= | ||
| + | |boiling point comment= | ||
| + | |sublimation point K= | ||
| + | |sublimation point C= | ||
| + | |sublimation point F= | ||
| + | |sublimation point ref= | ||
| + | |sublimation point comment= | ||
| + | |density gplstp= | ||
| + | |density gplstp ref= | ||
| + | |density gplstp comment= | ||
| + | |density gpcm3nrt=11.7 | ||
| + | |density gpcm3nrt ref= | ||
| + | |density gpcm3nrt comment= | ||
| + | |density gpcm3nrt 2= | ||
| + | |density gpcm3nrt 2 ref= | ||
| + | |density gpcm3nrt 2 comment= | ||
| + | |density gpcm3nrt 3= | ||
| + | |density gpcm3nrt 3 ref= | ||
| + | |density gpcm3nrt 3 comment= | ||
| + | |density gpcm3mp= | ||
| + | |density gpcm3mp ref= | ||
| + | |density gpcm3mp comment= | ||
| + | |density gpcm3bp= | ||
| + | |density gpcm3bp ref= | ||
| + | |density gpcm3bp comment= | ||
| + | |molar volume= | ||
| + | |molar volume unit = | ||
| + | |molar volume ref= | ||
| + | |molar volume comment= | ||
| + | |triple point K= | ||
| + | |triple point kPa= | ||
| + | |triple point ref= | ||
| + | |triple point comment= | ||
| + | |triple point K 2= | ||
| + | |triple point kPa 2= | ||
| + | |triple point 2 ref= | ||
| + | |triple point 2 comment= | ||
| + | |critical point K= | ||
| + | |critical point MPa= | ||
| + | |critical point ref= | ||
| + | |critical point comment= | ||
| + | |heat fusion=13.81 | ||
| + | |heat fusion ref= | ||
| + | |heat fusion comment= | ||
| + | |heat fusion 2= | ||
| + | |heat fusion 2 ref= | ||
| + | |heat fusion 2 comment= | ||
| + | |heat vaporization=514 | ||
| + | |heat vaporization ref= | ||
| + | |heat vaporization comment= | ||
| + | |heat capacity=26.23 | ||
| + | |heat capacity ref= | ||
| + | |heat capacity comment= | ||
| + | |heat capacity 2= | ||
| + | |heat capacity 2 ref= | ||
| + | |heat capacity 2 comment= | ||
| + | |vapor pressure 1=2633 | ||
| + | |vapor pressure 10=2907 | ||
| + | |vapor pressure 100=3248 | ||
| + | |vapor pressure 1 k=3683 | ||
| + | |vapor pressure 10 k=4259 | ||
| + | |vapor pressure 100 k=5055 | ||
| + | |vapor pressure ref= | ||
| + | |vapor pressure comment= | ||
| + | |vapor pressure 1 2= | ||
| + | |vapor pressure 10 2= | ||
| + | |vapor pressure 100 2= | ||
| + | |vapor pressure 1 k 2= | ||
| + | |vapor pressure 10 k 2= | ||
| + | |vapor pressure 100 k 2= | ||
| + | |vapor pressure 2 ref= | ||
| + | |vapor pressure 2 comment= | ||
| + | <!-- Atomic properties --> | ||
| + | |atomic properties comment= | ||
| + | |oxidation states='''4''', 3, 2, 1 | ||
| + | |oxidation states ref= | ||
| + | |oxidation states comment=(a weakly basic oxide) | ||
| + | |electronegativity=1.3 | ||
| + | |electronegativity ref= | ||
| + | |electronegativity comment= | ||
| + | |ionization energy 1=587 | ||
| + | |ionization energy 1 ref= | ||
| + | |ionization energy 1 comment= | ||
| + | |ionization energy 2=1110 | ||
| + | |ionization energy 2 ref= | ||
| + | |ionization energy 2 comment= | ||
| + | |ionization energy 3=1930 | ||
| + | |ionization energy 3 ref= | ||
| + | |ionization energy 3 comment= | ||
| + | |number of ionization energies= | ||
| + | |ionization energy ref= | ||
| + | |ionization energy comment= | ||
| + | |atomic radius=179.8 | ||
| + | |atomic radius ref= | ||
| + | |atomic radius comment= | ||
| + | |atomic radius calculated= | ||
| + | |atomic radius calculated ref= | ||
| + | |atomic radius calculated comment= | ||
| + | |covalent radius=206±6 | ||
| + | |covalent radius ref= | ||
| + | |covalent radius comment= | ||
| + | |Van der Waals radius= | ||
| + | |Van der Waals radius ref= | ||
| + | |Van der Waals radius comment= | ||
| + | <!-- Miscellanea --> | ||
| + | |crystal structure= | ||
| + | |crystal structure prefix= | ||
| + | |crystal structure ref= | ||
| + | |crystal structure comment=Face-centred cubic (fcc) | ||
| + | |crystal structure 2= | ||
| + | |crystal structure 2 prefix= | ||
| + | |crystal structure 2 ref= | ||
| + | |crystal structure 2 comment= | ||
| + | |speed of sound= | ||
| + | |speed of sound ref= | ||
| + | |speed of sound comment= | ||
| + | |speed of sound rod at 20=2490 | ||
| + | |speed of sound rod at 20 ref= | ||
| + | |speed of sound rod at 20 comment= | ||
| + | |speed of sound rod at r.t.= | ||
| + | |speed of sound rod at r.t. ref= | ||
| + | |speed of sound rod at r.t. comment= | ||
| + | |thermal expansion= | ||
| + | |thermal expansion ref= | ||
| + | |thermal expansion comment= | ||
| + | |thermal expansion at 25=11 | ||
| + | |thermal expansion at 25 ref= | ||
| + | |thermal expansion at 25 comment= | ||
| + | |thermal conductivity=54 | ||
| + | |thermal conductivity ref= | ||
| + | |thermal conductivity comment= | ||
| + | |thermal conductivity 2= | ||
| + | |thermal conductivity 2 ref= | ||
| + | |thermal conductivity 2 comment= | ||
| + | |thermal diffusivity= | ||
| + | |thermal diffusivity ref= | ||
| + | |thermal diffusivity comment= | ||
| + | |electrical resistivity= | ||
| + | |electrical resistivity unit prefix= | ||
| + | |electrical resistivity ref= | ||
| + | |electrical resistivity comment= | ||
| + | |electrical resistivity at 0=157 | ||
| + | |electrical resistivity at 0 ref= | ||
| + | |electrical resistivity at 0 comment= | ||
| + | |electrical resistivity at 20= | ||
| + | |electrical resistivity at 20 ref= | ||
| + | |electrical resistivity at 20 comment= | ||
| + | |band gap= | ||
| + | |band gap ref= | ||
| + | |band gap comment= | ||
| + | |Curie point K= | ||
| + | |Curie point ref= | ||
| + | |Curie point comment= | ||
| + | |magnetic ordering=Paramagnetic | ||
| + | |magnetic ordering ref= | ||
| + | |magnetic ordering comment= | ||
| + | |tensile strength= | ||
| + | |tensile strength ref= | ||
| + | |tensile strength comment= | ||
| + | |Young's modulus=79 | ||
| + | |Young's modulus ref= | ||
| + | |Young's modulus comment= | ||
| + | |Shear modulus=31 | ||
| + | |Shear modulus ref= | ||
| + | |Shear modulus comment= | ||
| + | |Bulk modulus=54 | ||
| + | |Bulk modulus ref= | ||
| + | |Bulk modulus comment= | ||
| + | |Poisson ratio=0.27 | ||
| + | |Poisson ratio ref= | ||
| + | |Poisson ratio comment= | ||
| + | |Mohs hardness=3.0 | ||
| + | |Mohs hardness ref= | ||
| + | |Mohs hardness comment= | ||
| + | |Mohs hardness 2= | ||
| + | |Mohs hardness 2 ref= | ||
| + | |Mohs hardness 2 comment= | ||
| + | |Vickers hardness=295–685 | ||
| + | |Vickers hardness ref= | ||
| + | |Vickers hardness comment= | ||
| + | |Brinell hardness=390–1500 | ||
| + | |Brinell hardness ref= | ||
| + | |Brinell hardness comment= | ||
| + | |CAS number=7440-29-1 | ||
| + | |CAS number ref= | ||
| + | |CAS number comment= | ||
| + | <!-- History --> | ||
| + | |naming=After Thor, the Norse god of thunder | ||
| + | |predicted by= | ||
| + | |prediction date ref= | ||
| + | |prediction date= | ||
| + | |discovered by= Jöns Jakob Berzelius | ||
| + | |discovery date ref= | ||
| + | |discovery date=1829 | ||
| + | |first isolation by= | ||
| + | |first isolation date ref= | ||
| + | |first isolation date= | ||
| + | |discovery and first isolation by= | ||
| + | |named by= | ||
| + | |named date ref= | ||
| + | |named date= | ||
| + | |history comment label= | ||
| + | |history comment= | ||
| + | <!-- Isotopes --> | ||
| + | |isotopes= | ||
| + | |isotopes comment= | ||
| + | |engvar= | ||
| + | }} | ||
'''Thorium''' is a chemical element with the symbol '''Th''' and atomic number 90. | '''Thorium''' is a chemical element with the symbol '''Th''' and atomic number 90. | ||
==Properties== | ==Properties== | ||
===Chemical=== | ===Chemical=== | ||
| − | Thorium is a highly reactive metal. At room temperature, thorium is slowly attacked by water | + | Thorium is a highly reactive metal. At room temperature, thorium is slowly attacked by water but does not readily dissolve in most common acids, the exception being hydrochloric acid. It will dissolve in concentrated nitric acid containing a small amount of catalytic fluoride or fluorosilicate ions. At high temperatures, it is easily attacked by [[oxygen]], [[hydrogen]], [[nitrogen]], the halogens, and [[sulfur]]. Finely divided thorium is highly pyrophoric. Thorium burns with a bright white flame in the air. |
===Physical=== | ===Physical=== | ||
| Line 13: | Line 285: | ||
The acquisition of pure metal is problematic, as there are almost no companies that will sell very small samples to individuals. Element collector Max Whitby explained in a [http://www.youtube.com/watch?v=W1yuucJfB6E YT video] that there are extremely few companies that will sell small samples of thorium, even chemical lab suppliers. He also discovered that shipping it outside requires a heavy-duty license for radioactive materials, as he discovered when he was visited by authorities. | The acquisition of pure metal is problematic, as there are almost no companies that will sell very small samples to individuals. Element collector Max Whitby explained in a [http://www.youtube.com/watch?v=W1yuucJfB6E YT video] that there are extremely few companies that will sell small samples of thorium, even chemical lab suppliers. He also discovered that shipping it outside requires a heavy-duty license for radioactive materials, as he discovered when he was visited by authorities. | ||
| − | == | + | ==Isolation== |
Metallic thorium can be extracted by reducing [[thorium dioxide]] with [[calcium]] in an inert atmosphere: | Metallic thorium can be extracted by reducing [[thorium dioxide]] with [[calcium]] in an inert atmosphere: | ||
:ThO<sub>2</sub> + 2 Ca → 2 CaO + Th | :ThO<sub>2</sub> + 2 Ca → 2 CaO + Th | ||
| + | |||
| + | Dissolving TIG welding rods in acids or alkali is difficult, as tungsten is very resistant to most reagents, and bulk metal is even more inert. However, one can successfully dissolve them in concentrated H<sub>2</sub>O<sub>2</sub>, which forms tungstic acid and ThO<sub>2</sub>. | ||
==Projects== | ==Projects== | ||
| Line 33: | Line 307: | ||
===Disposal=== | ===Disposal=== | ||
| − | Thorium and its | + | Thorium and its compounds, are toxic, and it is recommended to avoid dumping the compounds in the environment and instead should be taken to waste disposal facilities. |
| − | If the thorium was extracted from its natural ore that was taken from an area where the said ore can be easily collected, it's not entirely a bad idea to dispose of the ore wastes as well as thorium compounds residues in the said area, as the | + | If the thorium was extracted from its natural ore that was taken from an area where the said ore can be easily collected, it's not entirely a bad idea to dispose of the ore wastes as well as thorium compounds residues in the said area, as the said area is already naturally contaminated and radioactive and the amount of ore waste is (almost) the same as the one you originally picked it up. |
==References== | ==References== | ||
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*[http://www.sciencemadness.org/talk/viewthread.php?tid=29927 The trials and tribulations of Thorium production] | *[http://www.sciencemadness.org/talk/viewthread.php?tid=29927 The trials and tribulations of Thorium production] | ||
*[http://www.sciencemadness.org/talk/viewthread.php?tid=11275 Thorium Separation From TIG Electrodes] | *[http://www.sciencemadness.org/talk/viewthread.php?tid=11275 Thorium Separation From TIG Electrodes] | ||
| + | *[https://www.sciencemadness.org/whisper/viewthread.php?tid=158808 Thorium from monazite sand] | ||
[[Category:Elements]] | [[Category:Elements]] | ||
| Line 48: | Line 323: | ||
[[Category:Radioactives]] | [[Category:Radioactives]] | ||
[[Category:Heavy metal toxicants]] | [[Category:Heavy metal toxicants]] | ||
| + | [[Category:Pyrophoric materials]] | ||
[[Category:F-block]] | [[Category:F-block]] | ||
Latest revision as of 20:50, 23 October 2022
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Thorium, Th | ||||
| Appearance | Silvery-grey, often black tarnish | ||||
| Thorium in the periodic table | |||||
| |||||
| Atomic number | 90 | ||||
| Standard atomic weight (Ar) | 232.0377(4) | ||||
| Element category | Actinides | ||||
| Group, block | n/a; f-block | ||||
| Period | period 7 | ||||
| Electron configuration | [Rn] 6d2 7s2 | ||||
per shell | 2, 8, 18, 32, 18, 10, 2 | ||||
| Physical properties | |||||
| Silvery-gray | |||||
| Phase | Solid | ||||
| Melting point | 2023 K (1750 °C, 3182 °F) | ||||
| Boiling point | 5061 K (4788 °C, 8650 °F) | ||||
| Density near r.t. | 11.7 g/cm3 | ||||
| Heat of fusion | 13.81 kJ/mol | ||||
| Heat of | 514 kJ/mol | ||||
| Molar heat capacity | 26.23 J/(mol·K) | ||||
| pressure | |||||
| Atomic properties | |||||
| Oxidation states | 4, 3, 2, 1 (a weakly basic oxide) | ||||
| Electronegativity | Pauling scale: 1.3 | ||||
| energies |
1st: 587 kJ/mol 2nd: 1110 kJ/mol 3rd: 1930 kJ/mol | ||||
| Atomic radius | empirical: 179.8 pm | ||||
| Covalent radius | 206±6 pm | ||||
| Miscellanea | |||||
| Crystal structure | Face-centred cubic (fcc) | ||||
| Speed of sound thin rod | 2490 m/s (at 20 °C) | ||||
| Thermal expansion | 11 µm/(m·K) (at 25 °C) | ||||
| Thermal conductivity | 54 W/(m·K) | ||||
| Electrical resistivity | 157 Ω·m (at 0 °C) | ||||
| Magnetic ordering | Paramagnetic | ||||
| Young's modulus | 79 GPa | ||||
| Shear modulus | 31 GPa | ||||
| Bulk modulus | 54 GPa | ||||
| Poisson ratio | 0.27 | ||||
| Mohs hardness | 3.0 | ||||
| Vickers hardness | 295–685 MPa | ||||
| Brinell hardness | 390–1500 MPa | ||||
| CAS Registry Number | 7440-29-1 | ||||
| History | |||||
| Naming | After Thor, the Norse god of thunder | ||||
| Discovery | Jöns Jakob Berzelius (1829) | ||||
Thorium is a chemical element with the symbol Th and atomic number 90.
Contents
Properties
Chemical
Thorium is a highly reactive metal. At room temperature, thorium is slowly attacked by water but does not readily dissolve in most common acids, the exception being hydrochloric acid. It will dissolve in concentrated nitric acid containing a small amount of catalytic fluoride or fluorosilicate ions. At high temperatures, it is easily attacked by oxygen, hydrogen, nitrogen, the halogens, and sulfur. Finely divided thorium is highly pyrophoric. Thorium burns with a bright white flame in the air.
Physical
Thorium is a soft, paramagnetic, bright silvery radioactive actinide metal. Pure thorium is soft, very ductile. Because thorium melts at 1750 °C and boils at 4788 °C, it has one of the widest liquid range of all metals.
Availability
Thorium was available in the past as thorium dioxide in gas mantles. Certain heat resistant ceramics contain thoria. Small amounts of thorium are added in TIG welding rods. Old gas mantles can contain amounts of thorium dioxide.
The acquisition of pure metal is problematic, as there are almost no companies that will sell very small samples to individuals. Element collector Max Whitby explained in a YT video that there are extremely few companies that will sell small samples of thorium, even chemical lab suppliers. He also discovered that shipping it outside requires a heavy-duty license for radioactive materials, as he discovered when he was visited by authorities.
Isolation
Metallic thorium can be extracted by reducing thorium dioxide with calcium in an inert atmosphere:
- ThO2 + 2 Ca → 2 CaO + Th
Dissolving TIG welding rods in acids or alkali is difficult, as tungsten is very resistant to most reagents, and bulk metal is even more inert. However, one can successfully dissolve them in concentrated H2O2, which forms tungstic acid and ThO2.
Projects
- Thorium halides
- Make thorium dioxide
- Firestarters
Handling
Safety
Thorium is highly reactive and pyrophoric. It is only mildly radioactive (232Th has a half-life of 14.05 billion years and is alpha radioactive), the radiation is too weak to penetrate the skin. Soluble thorium compounds are toxic and should be handled with proper protection.
Bulk thorium is difficult to ignite, but finely divided metal is highly pyrophoric.
Storage
As thorium will slowly react with the air, it should be stored under oil or under an inert atmosphere, in a container. Sealing it is not necessary. Being weak radioactive, thorium does not require radiation shielding (the storage container walls will effectively absorb the weak alpha radiation).
Disposal
Thorium and its compounds, are toxic, and it is recommended to avoid dumping the compounds in the environment and instead should be taken to waste disposal facilities.
If the thorium was extracted from its natural ore that was taken from an area where the said ore can be easily collected, it's not entirely a bad idea to dispose of the ore wastes as well as thorium compounds residues in the said area, as the said area is already naturally contaminated and radioactive and the amount of ore waste is (almost) the same as the one you originally picked it up.
