Silicon

After carbon silicon is the most abundant element on earth. Silicon is obtained by reducing sand (silica: SiO₂), with carbon.

Silicon exists in two forms;

• brown silicon is a powder
• crystalline (metallic) silicon is grey

The crystalline form is more widely used. Silicon has many applications in various industries:

• semiconductor industry as a result of its semiconducting properties
• as an alloying element in the manufacture of certain alloys (e.g. ferrosilicon, an alloy of iron and silicon which is used to introduce silicon into steel and cast iron)
• in the manufacture of glass.

Silicon Bronze

95 % Copper 4 % Silicon 1 % Manganese

Silicon carbide

Used extensively as a grinding compound and in abrasive wheels.

Trade name: Carborundum

Chemical formula: SiC

See also: Chemical Table.