Transcript Silicon: Si
By Sonal Somaiya And Kamakshi Mamtani Silicon • 2nd most common element in the world • Used in computer chips The Periodic Table Family: Metalloid Silicon The Discovery In 1809 Gay-Lussac and Thenard made silicon by passing silicon fluoride over heated potassium. At the time, they scientists did not know that it was an element. Silicon the element was discovered by Jons Jacob Berzelius who lived in Sweden in 1824. He isolated the substance and realized that it could not be broken down anymore. That meant that it was an element. Characteristic Properties Symbol Atomic Number Atomic Mass Melting Point Boiling Point Classification/ Family Density Standard State # of electrons in outer shell Si 14 20.855 1410o Celsius 2355o Celsius Metalloids 2.329 g/cm3 Solid Four (4) Properties • • • • • • • • Hard Gray Brittle Diamond shaped structure Capable of forming long chain molecules Metabolism and replication are not messy Semiconductor so it can be a n insulator and a conductor Has a cubic crystal structure Other Uses • • • • • • • • Combine with boron, gallium, phosphorus, arsenic, etc for use in transistors, solar cells, rectifier, and other electronic solid devices Used to make concrete, bricks Used in medicine for silicone implants Silica as sand is a principal ingredient in grass Silicone – important products of silicon, prepared by hydrolsing a silicon organic chloride Diatoms, some protozoa, some sponges, and some plants use SIO2 as structural matter. Elemental silicon has been used in lasers to produce coherent light at 456nm. In the form of silicon dioxide, silicon is used in optical fiber An optical fiber is a glass thread that conducts light Silicon is also used to make glass when heated to about 1600o, it melts and makes silicon fuse added to other metals to make glass Helpful Properties in Computer Chips They make it useful in computer chips because silicon can be made to change it’s conductivity over very short distances. In turn, this makes it possible for the circuit components to be microscopically small.. Because of silicon’s semi conductivity, it does not conduct electricity as efficiently as conductors Elements in Computer Chips Boron is used in computer chips because it is a semiconductor. Semiconductors can either be a conductor or an insulator. Aluminum and copper are used in computer chips because they are conductors. They conduct electricity. Gold is only used to connect the actual chip to the package. Gold is also a semiconductor meaning that it can be a conductor or an insulator. Silicon crystals are also used. They are made from refined quartz crystals. Bibliography -www.mccsc.edu/unrapp/elementquest/student/silicon/history.html - www.chemicalelements.com - www.enviromentalchemistry.com -www.intel.com/education/makingchips/preparation.htm -www.chemistry.about.com/library/blsi.html -www.ajkids.com/main/followup.asp?… -Jack Challoner, The Visual Dictionary of Chemistry, DK Publishing Inc., New York City, 1996 -P.W Atkins, The Periodic Kingdom, Basic Books, New York, 1995 - Brian Kapp, Elements Silicon, Atlantic Europe Publishing Co. Ltd. Danbury Connecticut ,1996 -www.ch.com.ac.uk/SGTL/elements/ -www.tcaep.co.uk/science/periodic/e1014.htm -www.webelements.com -www.fic.uc.pt/st2.5/scenes-e/elem/e1014.html -www. Infoplease.com/periodictable.php?group=J THE END