Argentium Sterling silver is a modern sterling silver alloy which modifies the traditional alloy 92.5 silver 7.5 copper by replacing some of the copper with the metalloid germanium ref Peter Johns 1997 Firestain Resistant Silver Alloys. Santa Fe Symposium On Jewelery Manufacturing Technology. ISBN 0 931913 25 X ref . As it retains the 92.5 silver content of the traditional alloy, it is still referred to as sterling silver. Origins and description Argentium Silver is the result of research by Peter Johns at the Art and Design Research Institute ADRI , School of Art & Design, Middlesex University . The project began in 1990 with research on the effects of germanium additions to silver alloy s. Germanium was discovered to impart the following properties to sterling silver ref Johns, Peter and Davis, Sam 2007 The properties and applications of Argentium TM Sterling Silver. In 31st IPMI Conference International Precious Metals Institute ref Firescale elimination High tarnish resistance Precipitation hardening and simple heat hardening properties Increased ductility Increased thermal and electrical resistance making alloys suitable for welding and laser forming Environmental advantages associated with not having to remove or plate over firescale Many of these properties significantly affect the traditional methods of working silver. For instance the absence of firescale eliminates tedious and time consuming steps required by the silver worker using traditional sterling silver. It also eliminates the need for plating the final product which is often done on manufactured items because of the problems introduced by firescale. Tarnish resistance is of significant importance to both silver workers and the wearer of silver jewellery. Argentium Silver is patented and trademarked by Argentium Silver Company, UK. Physical properties Traditional sterling silver has a Solidus chemistry solidus melting temperature of 1475 F 802 C and a liquidus flow point of 1650 F 899 C . The solidu ... more details
In the United States Department of Defense US military , reactive materials RM are a new class of materials currently being investigated by the Office of Naval Research and others as a means to increase the lethality of direct hit or fragmentation warhead s. Reactive materials are similar to insensitive munitions Insensitive high explosives insensitive high explosives , but are usually thermite like pyrotechnic composition s of two or more nonexplosive solid materials, which stay inert and do not react with each other until subjected to a sufficiently strong mechanical, electrical or laser stimulus, after which they undergo fast burning or explosion with release of high amount of chemical energy in addition to their kinetic energy . Fragments or projectiles made of such materials have therefore greater damaging effect than inert ones, with expected lethality increase up to 500 . The material classes under investigation are thermite s, intermetallic compounds, metal polymer mixtures e.g. magnesium teflon viton like , metastable intermolecular composite s MIC , matrix materials, and hydride s. ref cite book title Advanced Energetic Materials author Committee on Advanced Energetic Materials and Manufacturing Technologies, National Research Council year 2004 publisher National Academies Press location Washington D.C., USA isbn 978 0 309 09160 2 pages 20 23 url http books.nap.edu openbook.php?record id 10918&page 20 accessdate 16 August 2011 ref These materials must be strong enough to act as structural components, be sufficiently stable to survive handling and launch, to penetrate a target, and sufficiently unstable to reliably ignite on impact. The mixtures under investigation include one or more finely powdered down to nanoparticle size metalloid s or metals like aluminium , magnesium , zirconium , titanium , tungsten , tantalum , or hafnium , with one or more oxidizers like teflon or other fluoropolymer , pressed or Sintering sintered or bonded by other method to a c ... more details
conduct electricity , and the nonmetals , which do not, with a small group the metalloid s having ... s, halogen s, lanthanide s, post transition metal s or other metals , metalloid s, noble gas es, nonmetal ... identified as a metalloid and the others identified as nonmetals. States of matter Another commonly ... more details
group consists of two non metals, two metalloid s, one metal , and one synthetic presumably ... element color Metalloids Metalloid s bgcolor element color Poor metals Poor metal s atomic ... more details
metal Ne 3s sup 2 sup 3p sup 1 sup bgcolor cccc99 14 Si Silicon Metalloid Ne 3s sup 2 sup 3p sup 2 ... Silicon Silicon symbol Si is a tetravalent metalloid . It is less reactive than its chemical analog ... , the metalloid directly below it in the table. Controversy about silicon s character dates to its ... more details
A heavy metal is a member of a loosely defined subset of elements that exhibit metallic properties. It mainly includes the transition metal s, some metalloid s, lanthanide s, and actinide s. Many different definitions have been proposed some based on density , some on atomic number or atomic weight , and some on chemical properties or toxic metal toxicity . ref name Duffus The term heavy metal has been called a misinterpretation in an IUPAC technical report due to the contradictory definitions and its lack of a coherent scientific basis . ref name Duffus John H. Duffus Heavy metals a meaningless term? IUPAC Technical Report Pure and Applied Chemistry, 2002, Vol. 74, pp. 793 807. doi 10.1351 pac200274050793 ref There is an alternative term toxic metal , for which no consensus of exact definition exists either. As discussed below, depending on context, heavy metal can include elements lighter than carbon and can exclude some of the heaviest metals. Heavy metals occur naturally in the ecosystem with large variations in concentration. In modern times, anthropogenic sources of heavy metals, i.e. pollution, have been introduced to the ecosystem. Waste derived fuels are especially prone to contain heavy metals, so heavy metals are a concern in consideration of waste as fuel. Citation needed October 2011 date October 2011 Relationship to living organisms Living organisms require varying amounts of heavy metals . Iron , cobalt , copper , manganese , molybdenum , and zinc are required by humans. Excessive levels can be damaging to the organism. Other heavy metals such as mercury element mercury , plutonium , and lead are toxic metal s that have no known vital or beneficial effect on organisms Citation needed date February 2010 , and their accumulation over time in the bodies of animal s can cause serious illness. Certain elements that are normally toxic are, for certain organisms or under certain conditions, beneficial. Examples include vanadium , tungsten , and even cadmium ... more details
Infobox mineral name Stibnite category Sulfide mineral boxwidth boxbgcolor image Stibnite.jpg caption Stibnite in the Carnegie Museum of Natural History formula Sb sub 2 sub S sub 3 sub strunz 02.DB.05a symmetry Orthorhombic dipyramidal br H M symbol 2 m 2 m 2 m br Space group Pbnm unit cell a 11.229 ngstrom , b 11.31 , br c 3.8389 Z 4 molweight color Lead gray, tarnishing blackish or iridescent in polished section, white habit Massive, radiating and elongated crystals. Massive and granular system Orthorhombic twinning Rare cleavage Perfect and easy on 010 imperfect on 100 and 110 fracture Subconchoidal tenacity Highly flexible but not elastic slightly sectile mohs 2 luster Splendent on fresh crystals surfaces, otherwise metallic refractive opticalprop birefringence pleochroism streak Similar to color gravity 4.63 melt fusibility diagnostic solubility decomposed with hydrochloric acid diaphaneity Opaque other Anisotropism Strong references ref name Handbook http rruff.geo.arizona.edu doclib hom stibnite.pdf Stibnite . Handbook of Mineralogy ref ref name Mindat http www.mindat.org min 3782.html Stibnite . Mindat.org ref ref name Webmin http www.webmineral.com data Stibnite.shtml Stibnite . Webmineral ref var1 Metastibnite var1text Earthy, reddish deposits Stibnite , sometimes called antimonite , is a sulfide mineral with the chemical formula formula antimony Sb sub 2 sub sulfur S sub 3 sub . This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony . ref Sabina C. Grund, K. Hanusch, H. J. Breunig, H. U. Wolf, Antimony and Antimony Compounds in Ullmann s Encyclopedia of Industrial Chemistry 2006, Wiley VCH, Weinheim. DOI 10.1002 14356007.a03 055.pub2 ref The name is from the Greek stibi through the Latin stibium as the old name for the mineral and the element antimony. ref name Handbook ref name Mindat As an antimony sulfide, it is potentially toxic and should be handled with care. Struct ... more details
Intermetallics or intermetallic compounds is a term that is used in a number of different ways. Most commonly it refers to solid state phases involving metal s. There is a research definition adhered to generally in scientific publications, and a wider common use term. There is also a completely different use in coordination chemistry , where it has been used to refer to complexes containing two or more different metals. Although the term intermetallic compounds , as it applies to solid phases, has been in use for many years, its introduction was regretted, for example by Hume Rothery in 1955. ref Electrons, atoms, metals and alloys W. Hume Rothery Publisher The Louis Cassier Co. Ltd 1955 ref Note that many intermetallic compounds are often simply called alloys , although this is somewhat of a misnomer. Both are metallic phases containing more than one element, but in alloys, the various elements substitute randomly for one another in the crystal structure , forming a solid solution with a range of possible compositions, while in intermetallic compounds, different elements are ordered into different sites in the structure, with distinct local environments and often a well defined, fixed stoichiometry. Complex structures with very large unit cell s can be formed. Definitions Research definition Schulze in 1967, ref G. E. R. Schulze Metallphysik, Akademie Verlag, Berlin 1967 ref defined intermetallic compounds as solid phases containing two or more metallic elements, with optionally one or more non metallic elements, whose crystal structure differs from that of the other constituents. Under this definition the following are included Electron or Hume Rothery compounds Size packing phases. e.g. Laves phase s, Frank Kasper phase s and Nowotny phase s Zintl phase s The definition of a metal is taken to include the so called poor metals , i.e. aluminium, gallium, indium, thallium, tin and lead some, if not all, of the metalloid s, e.g. silicon, germanium, arsenic, antimony ... more details
Primary sources date September 2009 infobox music festival music festival name Hellfire Festival location Birmingham NEC National Exhibition Centre , Birmingham , England years active 2009 present dates February November genre Heavy metal music heavy metal , Thrash metal music thrash metal , Death metal music death metal website http www.hellfirefestival.com www.hellfirefestival.com The Hellfire Festival is a three day music festival currently held at Birmingham NEC National Exhibition Centre , Birmingham , England . The next edition of the festival will be held on November 6 to 8 2009. The first edition of the festival was held at the 02 Academy in Islington , London . Hellfire I The first edition of the Hellfire Festival was held from Friday, February 20 to Sunday, February 22 2009 at the 02 Academy in Islington , London . More than 32 bands appeared at the festival spread over two stages and across the three days. ref cite web url http www.hellfirefestival.com one ?page lineup title Hellfire One ref Tickets for the festival were priced at 16.50 Friday , 20.00 Saturday , 18.00 Sunday or 50 for a three day pass. class wikitable colspan 3 align center Main Stage Friday Saturday Sunday valign top align center width 200 Overkill band Overkill br Exodus band Exodus br Gama Bomb br Torture Squad valign top align center width 200 Firewind br Alestorm br Panic Cell br The More I See br The Defiled br Godsized valign top align center width 200 Breed 77 br Sabbat band Sabbat br Warrior Soul br Exit Ten br Anterior br Outcryfire br The Hollowed Earth Theory br Metalloid class wikitable colspan 3 align center Scuzz Stage Friday Saturday Sunday valign top align center width 200 Stage Closed valign top align center width 200 Annotations of an Autopsy br Trigger the Bloodshed br The Rotted br Burning Skies br Dead Beyond Buried br RSJ band RSJ br Scar My Eyes br valign top align center width 200 Malefice br Sacred Mother Tongue br Romeo Must Die br Forever Never br Cinders Fall ... more details
, and high electrical resistivity. One such typical material is a transition metal metalloid alloy, made from about 80 transition metal usually Fe, Co, or Ni and a metalloid component Boron B , Carbon ... more details
Distinguish2 the metalloid chemical element Silicon Wiktionary File Caulking.jpg thumb right Silicone caulk can be used as a basic sealant against water and air penetration. Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat resistant and elastomer rubber like, they are used in sealant s, adhesive s, lubricant s, medicine medical applications e.g., breast implants , cookware, and Thermal insulation insulation . Silicones are polymers that include silicon together with carbon , hydrogen , oxygen , and sometimes other chemical element s. Some common forms include silicone oil , silicone grease , silicone rubber , and silicone resin . Properties unreferenced section date February 2012 Some of the most useful properties of silicones include Low thermal conductivity Low chemical reactivity Low toxicity Thermal stability constancy of properties over a wide temperature range of 100 to 250 C . The ability to repel water and form watertight seals, although silicones are not hydrophobe s. Does not stick to many substrates, but adheres very well to others, e.g. glass. Does not support microbe microbiological growth. Silicones have excellent resistance to oxygen, ozone, and ultraviolet ultraviolet UV light . This property has led to widespread use of silicones in the construction industry e.g. coatings, fire protection, glazing seals and the automotive industry external gaskets, external trim . Good electrical insulation . Because silicone can be formulated to be electrically insulative or conductive, it is suitable for a wide range of electrical applications. They have high Permeation gas permeability at room temperature 25 C , the permeability of silicone rubber for such gases as oxygen is approximately 400 times Citation needed date May 2010 that of butyl rubber , making silicone useful for medical applications in which increased aeration ... element silicon , a crystalline metalloid widely used in computer s and other electronics electronic ... more details
into a solid material. Fuels Typical fuels are based on metal or metalloid powders. A flash powder ... a combustion instability suppressant Metalloid s Silicon high flame temperature, burns producing molten ... more details
style float right border 1px solid ccc margin 0.5em 0pt 0.8em 1.4em padding 3px important width 75px Group periodic table Group 14 Period periodic table Period Period 2 element 2 element cell File Diamond and graphite with scale.jpg 150px Diamond and graphite, two allotropes of carbon br 6 Carbon C Solid Nonmetals Primordial Period 3 element 3 element cell File SiliconCroda.jpg 150px Purified silicon br 14 Silicon Si Solid Metalloids Primordial Period 4 element 4 element cell File Polycrystalline germanium.jpg 150px Polycrystallline germanium br 32 Germanium Ge Solid Metalloids Primordial Period 5 element 5 element cell File Sn Alpha Beta.jpg 150px Alpha and beta tin, two allotropes of tin br 50 Tin Sn Solid Poor metals Primordial Period 6 element 6 element cell File Lead electrolytic and 1cm3 cube.jpg 150px Lead crystals br 82 Lead Pb Solid Poor metals Primordial Period 7 element 7 element cell 114 Ununquadium Uuq UnknownPhase Unknown chemical properties Synthetic colspan 3 center Legend colspan 2 style text align center border 1px solid AAAAAA background Element color Nonmetals small Nonmetal s small colspan 2 style text align center border 1px solid AAAAAA background Element color Metalloids small Metalloid s small colspan 2 style text align center border 1px solid AAAAAA background Element color Poor metals small Poor metal s small colspan 2 style text align center border element frame Primordial small Primordial element small colspan 2 style text align center border element frame Synthetic small Synthetic elements Synthetic small center The carbon group is a group periodic table periodic table group consisting of carbon C , silicon Si , germanium Ge , tin Sn , lead Pb , and ununquadium Uuq . In modern IUPAC notation, it is called Group 14 . In the old IUPAC and Chemical Abstracts Service CAS systems, it was called Group IVB and Group IVA , respectively. ref Fluck, E. New notations in the periodic table. Pure & App. Chem. 1988 , 60 , 431 436. http www.iupac.org ... more details
2 sup 5p sup 2 sup bgcolor cccc99 51 Sb Antimony Metalloid Kr 4d sup 10 sup 5s sup 2 sup 5p sup 3 sup bgcolor cccc99 52 Te Tellurium Metalloid Kr 4d sup 10 sup 5s sup 2 sup 5p sup 4 sup bgcolor ffff99 ... metalloid , it is found in nature mainly as the sulfide mineral stibnite Sb sub 2 sub S sub 3 sub ... 52. A brittle, mildly toxic, rare, silver white metalloid which looks similar to tin , tellurium is chemically ... more details
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