Atomic Number: 14
Atomic Weight: 28.0855
Discovery: Jons Jacob Berzelius 1824 (Sweden)
The melting point of silicon is 1410°C, boiling point is 2355°C, specific gravity is 2.33 (25°C), with a valence of 4.
Crystalline silicon has a metallic grayish color. Silicon is relatively inert, Silicon transmits over 95% of all infrared wavelengths (1.3-6.7 mm). Silicon doped with gallium, arsenic, boron, etc. is used to produce transistors, solar cells, rectifiers, and other important solid-state electronic devices.
Silicon's range from liquids to hard solids and have many useful properties, including use as adhesives, sealants, and insulators. Sand and clay are used to make building materials.
Silica is used to make glass, which has many useful mechanical, electrical, optical, and thermal properties.
It commonly occurs as the oxide and silicates, including sand, quartz, amethyst, agate, flint, jasper, opal, and citrine. Silicate minerals include granite, hornblende, feldspar, mica, clay, and asbestos.
Silicon may be prepared by heating silica and carbon in an electric furnace, using carbon electrodes. Amorphous silicon may be prepared as a brown powder, which can then be melted or vaporized.
The Czochralski process is used to produce single crystals of silicon for solid-state and semiconductor devices.
Hyperpure silicon may be prepared by a vacuum float zone process and by thermal decompositions of ultra-pure trichlorosilane in an atmosphere of hydrogen.
- Silicon is the eighth most abundant element in the universe.
- Silicon crystals for electronics must have a purity of one billion atoms for every non-silicon atom (99.9999999% pure).
- The most common form of silicon in the Earth's crust is silicon dioxide in the form of sand or quartz.
- Silicon, like water, expands as it changes from liquid to solid.
- Silicon oxide crystals in the form of quartz are piezoelectric. The resonance frequency of quartz is used in many precision timepieces.
|SILICON ATOM STRUCTURE|