Silicon Silicon is an element in the periodic table. Silicon is a metalloid, which means it has both properties of a metal and non-metal, so it is a member of Group 14(IVA)/the carbon family. Its atomic number is 14, its atomic mass is 28.0855 and its density is 2.65g/cm3. Silicon is a solid at room temperature with a boiling point of 3265⁰ C and a melting point of 1414⁰ C. Silicon exists in two allotropic forms, which means it has two forms that have different physical and chemical properties. The amorphous form is a brown powder and the crystalline form has a metallic luster and a grayish colour. Silicon is very hard, very brittle and is a semiconductor, meaning it is able to allow an electrical current pass through it better than a non-conductor, like glass or rubber, but not as good as a conductor, like copper or aluminum. Silicon always occurs as a compound, so it is always combined with other elements. Silicon dioxide is the most abundant compound in the earth’s crust, most commonly taking the form of sand. This compound is used in the manufacture of glass and bricks, paper and rubber, as a food additive, as an insulating material, in cosmetics, and many more! The compound of silicon with other elements like boron, gallium or arsenic is used in the making of electronic devices such as transistors, rectifiers, microchips, etc. Silicon carbide is one of the hardest substances known which can be used as an abrasive or as a refractory material. Silicones, which include silicon, are used for a wide range of things from toys and adhesives to surgical implants and automobile engine parts! Other important ways silicon is used are: in the manufacture of steel and alloys, and to help build the cell walls of plant and animal life when they extract the silica from the water. Although, people can develop a serious lung disease called silicosis if they breathe in too much of the dust of silica. But this is only a danger for workers in that type of environment!