THORIUM- MORE INFO

 

Thorium is a silvery-white metal that is quite similar in physical properties to lead.  It can be manipulated and shaped rather easily, with a 3.0 on Mohs hardness scale (equal to copper).  Only a handful of other elements surpass its melting point of 1750 degrees Celsius.

 

Thorium is soluble in acids but does not dissolve quickly in most, and reacts very slowly with Oxygen from the air (it takes months to lose its metallic luster).  It is a somewhat unstable radioactive element, and only has one naturally occurring isotope.  Dozens of other isotopes are even less stable and therefore cannot exist naturally.

 

Electron Configuration:

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 4f14 5d10 6s2 6p6 6d2 7s2

Shell 1- 2 electrons

Shell 2- 8 electrons

Shell 3- 18 electrons

Shell 4- 32 electrons

Shell 5- 18 electrons

Shell 6- 10 electrons

Shell 7- 2 electrons

 

Thorium is common among the Earth's crust, and is found in very small amounts within many soils and minerals (including Thorite, ThSi04, where Thorium was first discovered).

 

HISTORY AND DISCOVERY OF THORIUM

In 1815, Jöns Jacob Berzelius came across a mineral that contained an unknown substance, now known as thorite (ThSiO4).  In 1828, Reverend H. M. T. Esmark discovered a black mineral that his father (a renowned mineralogist) was unable to identify.  He sent a sample to Berzelius, who concluded that the mineral contained his unknown oxide as well.  His discovery of Thorium was first announced in 1829.  Thorium became very useful when Auer von Welsbach developed a thorium oxide-powered gas mantle in 1884.  As electricity replaced gas mantles , thorium became unimportant, but with the development of atomic energy, thorium became very important once again because of its nuclear properties.

 

HOW TO ISOLATE PURE THORIUM?

Thorium and its compounds are present in several minerals within the earth's crust.  The world currently produces about 30,000 metric tons of Thorium per year, and it's natural abundance in the earth's crust is about 5.0 x 10-4% (1 in every 200,000 atoms).  Thorium Dioxide (ThO2) can be extracted from minerals such as thorite and monazite and it can then be heated with Calcium to isolate the element.

ThO2(s) + 2Ca(s) + heat --> Th(s) + 2CaO(g)

 

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