From Sand to Solar Power

Silicon (Si – 14) is the eighth most common element. It is found primarily as Silicon Dioxide, in sand or quartz, which is the most common compound in the Earth's Crust. It also is present in a number of other crystalline forms in amethyst, flint and jasper. Used in glass, semiconductors (computer chips, hence the name Silicon Valley), solar cells and silicones – synthetic plastics.



Silicon is in the same group or column as Carbon in the Periodic Table; it also has four bonding electrons in its outer 3p shell. It is, however, considered a metalloid rather than a non-metal due to its greater mass. Silicon has been considered as a possible carbon replacement as a basis for life. Life on Earth is Carbon based but since Silicon has similar properties, it is postulated that there may be other worlds where Silicon, or a Silicon-Oxygen chain, has replaced Carbon in all life forms.

Diatoms, a form of plankton – a major oceanic food source, use Silicon to build their shells. These shells are being studied for possible use within nanotechnology since Diatoms can reliably manufacture microscopic valves of specific shapes.

Silicon is the main component of soda-lime glass, the most common form of glass, which consists of about 75% Silicon Dioxide. Glass is an amorphous (non-crystalline) solid material, typically brittle and optically transparent, but can be formed and colored by glass blowing or forming techniques into an unlimited variety of shapes.

Silicon has a higher density as a liquid so the solid floats in liquid Silicon much like ice floats in water. This is at a significantly higher temperature, however, as Silicon melts at 2577°F.

Silicon is used extensively in electronic integrated circuits such as computers since its electric conductive properties can be regulated to allow extremely small circuits to be built on the surface of pure silicon. Silicon wafers can also be used to generate electricity from light as light energizes the outer electrons causing a flow of electrons through the wafer to be passed to attached electrodes.

Finally Silicon is used as an oil, grease, rubber or resin in the form of Silicone. Silicone is a compound based on polysiloxane which is a long chain molecule based on a -Si-O-Si-O-backbone with two organic side chains on each Silicon atom. This makes it similar to Hydrocarbon molecules but with more versatility due to the many configurations afforded by varying the organic side chains to produce products ranging from an oil to a rubber to a hard plastic. Since Silicones are for the most part non-toxic, they are used in foods, personal care items, such as hair products, and implanted medical devices.

Silicon is an extremely abundant element as well as an extremely versatile one. New uses are continually being developed for this exceptional element and its compounds.