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Silicon
by Trevor Ball
Physical Geology
Spring 2015
  
 
 

Silicon

Silicon is the 14th element of the periodic table and the 8th most common element in the universe. While Silicon rarely appears in a pure state naturally, it is readily found in common materials like quartz and sand. Silicon is classified as a metalloid, meaning that is neither a metal nor a non-metal, but something in between the two. In a pure crystalline state Silicon possess a metallic grey color, is strong but brittle and chips easily.
 

 

Discovery
 

While Silicon was only discovered in the last three centuries, Quartz, which is made from Silicon, has been known for thousands of years. In 1789, French chemist Antoine Lavoisier proposed that there was a new chemical element that could be discovered in quartz and that this element would be very abundant. It could be said that his claim was an understatement since Silicon is the second most abundant element in the Earth’s crust at 28%, the only element larger presence in the crust is oxygen.
 

There were two potential discoveries of Silicon that followed. In 1808 Englishman Humphry Davy may have isolated partly pure Silicon without realizing it. Later in 1811, French chemists Joseph L. Gay-Lussac and Louis Jacques Thénard may have also made impure Silicon through their use of reacting potassium with silicon tetrafluoride. This created a reddish-brown solid that might have been amorphous Silicon, but they never tried to purify the substance.
 

The discovery of Silicon is credited to Swedish chemist Jöns Jakob Berzelius, who in 1823 created amorphous Silicon by reacting potassium fluorosilicate with potassium and purifying the product with repeated washing. He named the new material Silicium. Henri Étienne Sainte-Claire Deville discovered silicon’s more common, crystalline form, thirty-one years later. He electrolyzed impure sodium-aluminum chloride that contained about 10% Silicon thereby containing a slightly impure Silicon allotrope in 1854.
 

 

Applications
 

Due to Silicon’s presence in 90% of the Earth’s crust, it has found a variety of uses over time. Silicon in its most common natural state is usually used as building materials. This is because Silicon is present in things such as silica sand, clays, and most types of building stone. Silicates are used to create building mortar and combined with silica sand and gravel in order to create concrete.
 

Another of Silicon’s uses is the creation of glass and ceramics. Silicon is present in normal glass and whiteware ceramics such as porcelain. Silica based glass fibers are used to create optical fiber, fiberglass, and glass wool.
 


 

While the previous examples were all for uses of Silicon in its natural state there is a very important role pure Silicon plays in modern society. When in an extremely pure state Silicon can be doped with Arsenic, Boron, Gallium, or Phosphorous to produce Silicon for use in solid state electronics such as rectifiers, solar cells, and transistors which have an important place in modern electronic and space age industries.
 

 

Biological Role
 

While Silicon is readily abundant, there are very few species that make a great deal of use of it. Both fresh and salt-water diatoms use Silicon extracted from the water to create their cell walls and skeletons. The biggest use Humans have for silicon is the aorta, the primary artery of the human body.  Silicon is needed to synthesize elastin and collagen, and the Aorta has the highest concentration of elastin and silicon in the human body.

 

Works Cited

  http://education.jlab.org/itselemental/ele014.html

  http://www.chemicool.com/elements/silicon.html

  http://www.rsc.org/periodic-table/element/14/silicon

  http://periodic.lanl.gov/14.shtml

  http://upload.wikimedia.org/wikipedia/commons/e/e9/SiliconCroda.jpg

  http://www.chemistryexplained.com/photos/silicon-3311.jpg

  http://www.watchprojects.com/wp-content/uploads/2013/08/silicon_revolution-atomic-symbol.jpg

  http://the189.com/wordpress/wp-content/uploads/2012/12/Porcelain-Creations-by-Nathalie-Derouet-6.jpg

  http://upload.wikimedia.org/wikipedia/commons/4/4a/Silizium_pulver.jpg