Silicon Facts (Atomic Number 14 or Si)

Silicon Facts (Atomic Number 14 or Si) Silicon is a metalloid element with atomic number 14 and element symbol Si. In pure form, it is a brittle, hard solid with a blue-gray metallic luster. It is best known for its importance as a semiconductor. Fast Facts: Silicon Element Name: SiliconElement Symbol: SiAtomic Number: 14Appearance: Crystalline metallic solidGroup: Group 14 (Carbon Group)Period: Period 3Category: MetalloidDiscovery: Jà ¶ns Jacob Berzelius (1823) Silicon  Basic Facts Atomic Number: 14 Symbol: Si Atomic Weight: 28.0855 Discovery: Jons Jacob Berzelius 1824 (Sweden) Electron Configuration: [Ne]3s23p2 Word Origin: Latin: silicis, silex: flint Properties: 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, but it is attacked by dilute alkali and by halogens. Silicon transmits over 95% of all infrared wavelengths (1.3-6.7 mm). Uses: Silicon is one of the most widely used elements. Silicon is important to plant and animal life. Diatoms extract silica from water to build their cell walls. Silica is found in plant ashes and in the human skeleton. Silicon is an important ingredient in steel. Silicon carbide is an important abrasive and is used in lasers to produce coherent light at 456.0 nm. Silicon doped with gallium, arsenic, boron, etc. is used to produce transistors, solar cells, rectifiers, and other important solid-state electronic devices. Silicone is a class of useful compounds made from silicon. Silicones 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. Sources: Silicon makes up 25.7% of the earths crust, by weight, making it the second most abundant element (exceeded by oxygen). Silicon is found in the sun and stars. It is a principal component of the class of meteorites known as aerolites. Silicon is also a component of tektites, a natural glass of uncertain origin. Silicon is not found free in nature. 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. Preparation: 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. Element Classification: Semimetallic Isotopes: There are known isotopes of silicon ranging from Si-22 to Si-44. There are three stable isotopes: Al-28, Al-29, Al-30. Silicon Physical Data Density (g/cc): 2.33Melting Point (K): 1683Boiling Point (K): 2628Appearance: Amorphous form is brown powder; crystalline form has a grayAtomic Radius (pm): 132Atomic Volume (cc/mol): 12.1Covalent Radius (pm): 111Ionic Radius: 42 (4e) 271 (-4e)Specific Heat (20 °C J/g mol): 0.703Fusion Heat (kJ/mol): 50.6Evaporation Heat (kJ/mol): 383Debye Temperature (K): 625.00Pauling Negativity Number: 1.90First Ionizing Energy (kJ/mol): 786.0Oxidation States: 4, -4Lattice Structure: DiagonalLattice Constant (Ã…): 5.430CAS Registry Number: 7440-21-3 Pure silicon has a shiny, metallic luster. Martin Konopka / EyeEm, Getty Images Silicon Trivia 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 Earths 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. Sources Cutter, Elizabeth G. (1978). Plant Anatomy. Part 1 Cells and Tissues (2nd ed.). London: Edward Arnold. ISBN 0-7131-2639-6.Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.Voronkov, M. G. (2007). Silicon era. Russian Journal of Applied Chemistry. 80 (12): 2190. doi:10.1134/S1070427207120397Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.Zulehner, Werner; Neuer, Bernd; Rau, Gerhard, Silicon, Ullmanns Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a23_721