Silicon (Si)

Stable Isotopes

Unstable Isotopes

In 1800, Sir Humphry Davy thought silica to be a compound and not an element; but in 1811, Gay Lussac and Louis Jacques Thénard probably prepared impure amorphous silicon by heating potassium with silicon tetrafluoride. In 1824 Jöns Jakob Berzelius prepared amorphous silicon by the same general method. Henri Deville in 1854 first prepared crystalline silicon, the second allotropic form of the element. From the Latin word silex, silicis, flint

Discoverers	Jöns Berzelius
Discovery Location	Sweden
Discovery Year	1824
Name Origin	Latin: silex, silicus, (flint).

If breathed in as a fine silica/silicate dust, it may cause chronic respiratory problems

Silicon also has the unusual property that it expands as it freezes

In the form of sand and clay it is used to make concrete and brick; it is a useful refractory material for high-temperature work, and in the form of silicates it is used in making enamels, pottery, etc. Silica, as sand, is a principal ingredient of glass. Silicon chips are the basis of modern electronic and computing. Silicon carbide, more commonly called carborundum is used in abrasives. Used in glass as silicon dioxide (SiO2). Silicon carbide (SiC) is one of the hardest substances known and used in polishing. Also the crystalline form is used in semiconductors.

Makes up major portion of clay, granite, quartz (SiO2), and sand. Commercial production depends on a reaction between sand (SiO2) and carbon at a temperature of around 2200 °C.