Germanium

{| border="1" cellpadding="2" cellspacing="0" align="right" |- | colspan="2" cellspacing="0" cellpadding="2" | {| align="center" border="0" |- | colspan="2" align="center" | gallium – germanium – arsenic |- | rowspan="3" valign="center" | Silicon
Ge
Tin

|- | align="center" |

Periodic table (standard)

|} |- ! colspan="2" align=center bgcolor="#cccc99" | General |- | List of elements by name, List of elements by symbol, List of elements by number | germanium, Ge, 32 |- | periodic table series | metalloids |- | periodic table group, periodic table period, periodic table block | group 14 element, period 4 element, p-block |- | Density, Mohs hardness scale | 5323 kilogram per cubic metre, 6 |- | color | align="center" | greyish white
|- ! colspan="2" align="center" bgcolor="#cccc99" | Atomic properties |- | Atomic weight | 72.64 Atomic mass unit |- | Atomic radius (calc.) | 125 (125) picometre |- | Covalent radius | 122 pm |- | van der Waals radius | no data |- | Electron configuration | [argon]3d¹⁰ 4s² 4p² |- | electron 's per energy level | 2, 8, 18, 4 |- | Oxidation states (Oxide) | 4 (amphoteric) |- | Crystal structure | Diamond cubic |- ! colspan="2" align="center" bgcolor="#cccc99" | Physical properties |- | State of matter | solid |- | Melting point | 1211.4 Kelvin (1720.9 �Fahrenheit) |- | Boiling point | 3093 K (5108 �F) |- | Molar volume | 13.63 scientific notation10^-6 cubic metre per mole |- | Heat of vaporization | 330.9 kilojoule per mole |- | Heat of fusion | 36.94 kJ/mol |- | Vapor pressure | 0.0000746 Pascal at 1210 K |- | Speed of sound | 5400 metre per second at 293.15 K |- ! colspan="2" align="center" bgcolor="#cccc99" | Miscellaneous |- | Electronegativity | 2.01 (Pauling scale) |- | Specific heat capacity | 320 joule per kilogram-kelvin |- | Electrical conductivity | 1.45/(m�ohm) |- | Thermal conductivity | 59.9 watt per metre-kelvin |- | 1^st ionization potential | 762 kJ/mol |- | 2^nd ionization potential | 1537.5 kJ/mol |- | 3^rd ionization potential | 3302.1 kJ/mol |- | 4^th ionization potential | 4411 kJ/mol |- | 5^th ionization potential | 9020 kJ/mol |- ! colspan="2" align="center" bgcolor="#cccc99" | Most stable isotopes |- | colspan="2" | {| border="1" cellspacing="0" cellpadding="2" width="100%" |- ! Isotope ! natural abundance ! half-life ! decay mode ! decay energy (electron volt) ! decay product |- | ⁶⁸Ge | synthetic radioisotope | 1 E7_ s day | electron capture | - | ⁶⁸Gallium |- | ⁷⁰Ge | 21.23% | colspan="4" | Ge is stable isotope with 38 neutrons |- | ⁷¹Ge | syn. | 1 E5_ s day | electron capture | - | ⁷¹Gallium |- | ⁷²Ge | 27.66% | colspan="4" | Ge is stable with 40 neutrons |- | ⁷³Ge | 7.73% | colspan="4" | Ge is stable with 41 neutrons |- | ⁷⁴Ge | 35.94% | colspan="4" | Ge is stable with 42 neutrons |- | ⁷⁶Ge | 7.44% | colspan="4" | Ge is stable with 44 neutrons |} |- ! colspan="2" align="center" bgcolor="#cccc99" | SI units & standard temperature and pressure are used except where noted. |} Germanium is a chemical element in the periodic table that has the symbol Ge and atomic number 32. This is a lustrous, hard, silver-white, metalloid that is chemically similar to tin. Germanium forms a large number of organometallic compounds and is an important semiconductor material used in transistors. == Notable characteristics == Germanium is a hard, grayish-white element that has a metallic luster and the same crystal structure as diamond. In addition, it is important to note that germanium is a semiconductor, with electrical properties between those of a metal and an insulator. In its pure state, this metalloid is crystalline, brittle and retains its luster in air at room temperature. Zone refining techniques have led to the production of crystalline germanium for semiconductors that have an impurity of only one part in 10¹⁰. == History == In 1871 germanium (Latin ''Germania'' for Germany) was one of the elements that Dmitri Mendeleev predicted to exist as a missing analogue of the silicon group (Mendeleev called it "Mendeleev's predicted elements"). The existence of this element was proven by Clemens Winkler in 1886. This discovery was an important confirmation of Mendeleev's idea of element periodicity.

Property	Ekasilicon	Germanium
atomic mass	72	72.59
density (g/cm³)	5.5	5.35
melting point (�C)	high	947
color	gray	gray

The development of the germanium transistor opened the door to countless applications of solid-state electronics. From 1950 through the early 1970s, this area provided an increasing market for germanium, but then high purity silicon began replacing germanium in transistors, diode, and rectifiers. Silicon has superior electrical properties, but requires much higher purity samples—a purity which could not be commercially achieved in the early days. Meanwhile, demand for germanium in fiber optics communication networks, infrared night vision systems, and polymerization catalysts increased dramatically. These end uses represented 85% of worldwide germanium consumption for 2000. == Applications == Unlike most semiconductors, germanium has a small band gap, allowing it to efficiently respond to infrared light. It is therefore used in infrared spectroscopes and other optical equipment which require extremely sensitive infrared detectors. Its oxide's refractive index and dispersion properties make germanium useful in wide-angle camera lenses and in microscope objective lenses. Germanium transistors are still used in Stompbox by musicians who wish to reproduce the distinctive character of Fuzzbox from the early Rock and roll era. The alloy Silicon germanide (commonly referred to as "silicon-germanium", or SiGe) is rapidly becoming an important semiconductor material, for use in high speed integrated circuits. Circuits utilising the properties of Si-SiGe junctions can be much faster than those using silicon alone. Other uses: * Alloying agent; * Phosphor in fluorescent lamps; and as a * catalyst Certain compounds of germanium have low toxicity to mammals, but have toxic effects against certain bacterium. This property makes these compounds useful as chemotherapeutic agents. == Occurrence == This metal is found in argyrodite (sulfide of germanium and silver); coal; germanite; zinc ores; and other minerals. Germanium is obtained commercially from zinc ore processing smelter dust and from the combustion by-products of certain coals. A large reserve of this element is therefore in coal sources. This metaloid can be extracted from other metals by fractional distillation of its volatile tetrachloride. This technique permits the production of ultra-high purity germanium. In 1997 the cost of germanium was about United States dollar3 per gram. The yearend price for germanium in 2000 was $1,150 per kilogram (or $1.15 per gram). ==References== *[http://periodic.lanl.gov/elements/32.html Los Alamos National Laboratory – Germanium] == External links == *[http://www.webelements.com/webelements/elements/text/Ge/index.html WebElements.com – Germanium] *[http://environmentalchemistry.com/yogi/periodic/Ge.html EnvironmentalChemistry.com – Germanium] Metalloids Semiconductors

Germanium

Article changed over to new WikiProject Elements format by user:maveric149 === Information Sources === Some of the text in this entry was rewritten from [http://periodic.lanl.gov/elements/32.html Los Alamos National Laboratory - Germanium]. Additional text was taken directly from [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/ USGS Germanium Statistics and Information], from the Elements database 20001107 (via [http://www.dict.org dict.org]), Webster's Revised Unabridged Dictionary (1913) (via [http://www.dict.org dict.org]) and WordNet (r) 1.7 (via [http://www.dict.org dict.org]). Data for the table was obtained from the sources listed on the main page and WikiProject Elements but was reformatted and converted into SI units. ------ === Talk === ----- l == Electrical conductivity units are incorrect == Instead of Ohm it should be Ohm-m or Ohm-cm or somesuch.

Germanium

Germanium

See other meanings of words starting from letter:

G

GA | GB | GC | GD | GE | GF | GH | GI | GJ | GK | GL | GM | GN | GO | GP | GR | GS | GT | GU | GW | GX | GY | GZ |

Words begining with Germanium:

Germanium
Germanium
Germanium
Germanium_transistor