mercury element mercury chemical element symbol atomic number commonly known named heavy block element mercury metallic element liquid standard conditions temperature pressure element liquid conditions metals melt room temperature mercury occurs deposits world red pigment obtained grinding natural synthetic mercury float mercury switches mercury lamps devices concerns element led mercury largely phased clinical environments favor alternatives filled glass infrared based electronic instruments likewise mechanical pressure electronic strain gauge sensors replaced mercury mercury remains use scientific research applications dental restoration lighting electricity passed mercury lamp produces short wave light causes tube making visible light mercury poisoning result exposure water forms mercury mercury form mercury properties physical properties mercury heavy white liquid metal compared metals poor conductor heat fair conductor electricity freezing point boiling point exceptionally low metal addition mercury boiling point lowest metal freezing volume mercury decreases density changes liquid solid volume expansion solid mercury cut knife complete explanation mercury extreme deep realm quantum physics summarized follows mercury unique electron configuration fill available configuration strongly removal electron mercury similarly noble gases form weak bonds melt low temperatures stability shell presence filled shell shell poorly screens nuclear charge increases attractive interaction shell nucleus absence filled inner shell reason somewhat higher melting temperature metals melt easily addition unusually low boiling points chemical properties mercury react acid concentrated acid acid regia dissolve like silver mercury atmospheric hydrogen mercury solid mercury spill kits absorb mercury spill kits use activated carbon mercury metals gold silver form iron exception iron traditionally trade mercury row transition metals exception copper reluctant form elements readily form mercury include platinum common reducing agent organic synthesis high pressure lamps mercury readily combines aluminium form mercury aluminium pure metals come contact destroys aluminium layer protects metallic aluminium depth iron small amounts mercury seriously aluminium reason mercury allowed aboard aircraft circumstances risk forming exposed aluminium parts aircraft mercury common type liquid metal seven stable mercury abundant longest lived half life years half life days remaining half lives day studied active having spins respectively etymology modern chemical symbol mercury comes form greek word compound word meaning water silver root water silver liquid like water shiny like silver element named roman god mercury known speed mobility associated planet mercury symbol planet symbols metal sanskrit word means way mercury mercury metal common history mercury found egyptian tombs date china mercury use thought life heal maintain generally good health known exposure mercury leads adverse health effects emperor china allegedly buried tomb emperor contained rivers flowing mercury model land ruled representative rivers china killed drinking mercury jade mixture formulated causing liver failure mercury poisoning brain death intended eternal life ibn ibn second ruler egypt known reportedly built basin filled mercury lie air filled sleep november large quantities mercury discovered chamber feet year old pyramid known temple largest pyramid mexico jade statues jaguar remains box filled carved shells rubber balls ancient greeks mercury ancient romans major city maya civilization pool mercury found marker mercury medieval latin mercury metals thought mercury matter metals formed believed different metals produced varying quality quantity contained mercury gold mercury called attempts base metals gold goal mines spain italy dominated mercury production opening years ago new deposits found end 19th century occurrence mercury extremely rare element earth crust having average abundance mass parts million blend elements constitute majority mass mercury concentrated considering element abundance ordinary rock richest mercury contain mercury mass concentrated deposits mercury times average abundance found native metal rare minerals common ore mercury usually occur young belts rocks high density forced crust earth hot springs volcanic regions beginning invention process extract silver ore mercury mercury essential resource economy spain american colonies mercury extract silver lucrative mines new spain peru initially spanish crown mines southern spain supplied mercury colonies mercury deposits discovered new world tons mercury mined region peru course centuries following discovery deposits process later pan amalgamation process continued create great demand mercury treat silver late 19th century mines italy united_states mexico produced large proportion world supply completely mined case spain shut fall price mercury nevada mercury united_states closed price mercury highly volatile years pound mercury extracted heating current air equation extraction china producer mercury thirds global share followed countries believed production mercury copper processes recovery high mercury mining mercury hazardous historic causes mercury poisoning china prison labor private mining company recently 1950s create new mines thousands prisoners mining company establish new tunnels worker health functioning mines high risk european_union directive calling compact mandatory encouraged china open mines obtain mercury required manufacture environmental dangers concern particularly southern cities province southwest abandoned mercury processing sites contain hazardous waste piles water run sites recognized source ecological damage mercury mines suited use example santa county california purchased historic created county park site conducting extensive safety environmental analysis property chemistry mercury exists main states higher states rare mercury detected extraordinary conditions compounds mercury unlike lighter neighbors mercury usually forms simple stable compounds metal metal bonds mercury compounds feature stable derivatives include treatment compounds strong etc mercury mercury solid known compound formula standard mercury gas formula containing bond indicative tendency bond mercury forms mercury consist linear chains mercury centers capped positive charge example compounds mercury mercury common state main nature known form complexes adopt linear coordination geometry somewhat like best known mercury easily white solid forms coordination complexes typically mercury main mercury arises metal exposed air long periods elevated temperatures elements heating near demonstrated joseph early synthesis pure oxygen mercury poorly characterized neighbors gold silver soft metal mercury forms stable derivatives heavier mercury occurs nature ore brilliant pigment like forms reddish cubic form black form mercury mercury known derivatives mercury mercury useful infrared materials mercury form variety complex derivatives include base dimensional white known reagent potassium occasionally test owing tendency form deeply colored salt base mercury widely explosives higher states states non charged species extremely rare intermediate reactions report synthesis mercury compound mercury published 1970s claim synthesis mercury iii compound thought false compounds organic mercury compounds historically important little industrial value western world mercury rare example simple metal complexes react directly rings compounds usually coordinate linear geometry unlike compounds compounds react water usually formula volatile usually generic term compounds formula dangerous family compounds found water arise process known applications mercury primarily manufacture industrial chemicals electrical electronic applications especially ones measure high temperatures increasing mercury lamps applications slowly phased health safety regulations applications replaced toxic considerably expensive medicine mercury compounds medicine common today toxic effects mercury compounds widely understood edition manual featured compounds mercury ingredient dental called united_states organic compound use decline mercury widely speculated mercury based cause trigger children scientific studies showed evidence supporting link removed reduced trace amounts recommended children years age exception mercury compound minor cuts use countries mercury form common traditional especially traditional chinese medicine review safety found lead significant mercury heated consumed taken long term adverse effects effects typically form mercury appears toxic forms use traditional chinese medicine justified basis use clear today use mercury medicine greatly declined respects especially developed countries containing mercury invented early 18th late 19th centuries respectively early 21st century use declining banned countries states medical institutions senate passed legislation phase sale non mercury washington maine states ban mercury blood pressure devices mercury compounds found counter drugs including eye drops nasal inadequate data establish general recognition safety effectiveness mercury ingredients products mercury exist uses production produced common salt separate metallic gas usually salt dissolved water produce products process hydrogen commonly called far largest use mercury late 20th century mercury cell process called process metallic formed mercury reacted water produce industrial mercury releases 20th century came process modern plants claimed safe regard new production facilities built united_states membrane cell cell technologies produce laboratory uses medical especially high temperatures filled mercury gradually disappearing united_states non sale mercury fever banned mercury found liquid mirror transit use basin mercury form flat absolutely horizontal mirror useful determining absolute vertical perpendicular reference concave horizontal mirrors formed rotating liquid mercury disk form liquid formed reflecting focusing incident light cheaper conventional large mirror factor mirror points straight liquid mercury popular secondary reference called alternative standard hydrogen work potential half cells triple point mercury fixed point temperature standard international temperature scale dropping mercury hanging mercury drop use mercury use allows new available measurement new experiment niche uses mercury mercury lamps neon sign type advertising signs lamps low pressure lamps narrow lines traditionally optical position commercial lamps sold purpose reflecting ceiling light common practice mercury found electron tubes including mercury arc specialist medical care lamps skin mercury added cold filled lamps increase electrical filled lamp mercury dull spots fail light correctly lighting containing mercury bombarded oven pumped added neon filled tubes light produced inconsistent red blue spots initial burning process completed eventually light consistent dull blue color mercury widely manufacture minnesota state united_states ban intentionally added mercury giving tougher standard federal government study geometric mean mercury concentration identified previously source exposure skin care products mercury new_york_city residents population based showed mercury concentration levels higher consumers fish meals firearms mercury compound called mercury primary explosive mainly cartridge firearms historic uses historic applications use peculiar physical properties mercury especially dense liquid liquid metal quantities liquid mercury ranging grams recovered elite maya tombs ritual sites mercury mirrors purposes date classic period maya civilization example islamic spain filling decorative pools later american artist alexander built mercury fountain spanish pavilion world exhibition paris fountain display joan barcelona mercury inside heavy liquid form useful attractive irregular movement mercury moved inside plug use stopped environmental concerns illegal preparation modern fishing occurred lenses old float rotate bath mercury acted like bearing mercury blood pressure meter pumps laboratory instruments liquid high density nearly linear thermal expansion ideal role electrically liquid mercury switches including home mercury light switches installed prior tilt switches old fire tilt switches home owing acoustic properties mercury propagation medium delay line memory devices early digital computers mid-20th century experimental mercury turbines installed increase efficiency fossil fuel electrical power plants south meadow power plant employed mercury working fluid configuration secondary water circuit number years starting late 1920s drive improve plant efficiency plants built including station portsmouth went online idea catch industry wide weight mercury advent steam plants later years similarly liquid mercury nuclear proposed cooled liquid metal high density mercury requires energy mercury early engines electric space propulsion systems advantages mercury high molecular weight low energy low dual energy high liquid density liquid room temperature concerns environmental impact associated ground testing concerns eventual cooling spacecraft long duration operations use electric propulsion mercury fueled developed nasa lewis flown space electric rocket test spacecraft launched nasa flight facility flight followed flight mercury preferred engines hughes research laboratory performed studies finding gas suitable replacement preferred engines high molecular weight little noble gas nature high liquid density mild storage applications use chemical properties mercury mercury battery non battery primary cell common middle 20th century wide variety applications available sizes particularly button sizes constant voltage output long shelf life gave niche use camera light meters hearing aids mercury cell effectively banned countries 1990s concerns mercury mercury preserving wood developing mirrors anti discontinued discontinued handheld maze games cleaning road devices cars mercury compounds allegedly allied spies sabotage luftwaffe planes mercury paste applied bare aluminium causing metal rapidly cause structural failures process largest industrial use mercury 20th century separating mercury process paper location plants near paper mills cleaning products usage largely discontinued replaced technologies utilize membrane cells types batteries mercury cells production handheld games mercury gun barrel bore cleaner mid-19th centuries process called making felt hats animal skins orange solution term arose color mercury compound process separated fur solution produced highly toxic united_states public health service banned use mercury felt industry december psychological symptoms associated mercury poisoning inspired phrase mad lewis mad book alice adventures wonderland play words based older phrase character exhibit symptoms mercury poisoning gold silver mining historically mercury extensively hydraulic gold mining order help gold sink flowing water gravel mixture thin gold particles form mercury gold increase gold recovery rates large scale use mercury stopped 1960s mercury small scale clandestine gold estimated metric tons mercury california mining recovered mercury silver mining historic medicinal uses mercury known traditional medicine mercury known treat mercury compounds toxic symptoms confused believed treat blue mass mercury main ingredient prescribed 19th century numerous conditions including depression child bearing early 20th century mercury administered children yearly mercury containing sold widely banned countries safety mercury compounds extremely toxic handled care cases involving mercury certain light specific cleaning procedures avoid exposure contain spill physically merging smaller hard surfaces combining single larger pool easier removal gently pushing spill container vacuum cause greater dispersal mercury fine powder readily forms mercury ordinary temperatures area collected properly disposed cleaning surfaces clothing effective removing traces mercury advised kinds items exposed mercury spill mercury absorbed skin membranes mercury containers mercury sealed avoid heating mercury compounds mercury heated carried adequate ventilation order minimize exposure mercury toxic forms mercury organic compounds mercury cause chronic acute poisoning releases environment deposition rates mercury atmosphere ice deposit considered natural level exposure regional global sources significant effects volcanic increase atmospheric source times natural sources responsible approximately half atmospheric mercury emissions human generated half divided following estimated stationary coal fired power plants largest aggregate source mercury emissions includes power plants fueled gas mercury removed emissions coal orders magnitude higher emissions oil depending country gold production largest point sources mercury emissions largest gold mines release mercury gold accounted significant source atmospheric mercury eastern canada non metal production typically cement production waste disposal including municipal hazardous waste sewage production pig iron steel production mercury production mainly batteries sources estimates global human caused mercury emissions excluding burning important source regions recent atmospheric mercury contamination outdoor urban air measured study measured mercury levels indoor sites chosen represent cross section building types locations ages new_york area study found mercury concentrations significantly elevated outdoor concentrations range average mercury enters environment improper disposal land filling certain products products containing mercury include auto parts batteries medical products health concerns use reduction efforts cutting eliminating mercury products example mercury sold united_states decreased tons tons use alcohol instead mercury option mercury occasionally medical field accurate alcohol commonly replaced electronic commonly mercury widely certain scientific applications greater accuracy working range historically largest releases plant separation plant oak ridge tennessee plant operated 1950s 1960s records incomplete unclear government commissions estimated million pounds mercury industrial disaster dumping mercury compounds bay japan estimated people suffered severe mercury poisoning symptoms death known disease exposure health effects mercury exposure industrial commercial uses regulated countries world health organization treat mercury hazard established specific exposure limits environmental releases disposal mercury regulated primarily united_states environmental protection agency case control studies shown effects impaired skills sleep disturbance workers chronic exposure mercury low concentrations range study shown acute exposure hours calculated mercury levels resulted chest pain function evidence acute exposure mercury shown result profound central nervous system effects including reactions characterized tendency exposure resulted broad ranging functional disturbance including excessive continuing exposure fine develops violent muscular initially involves hands later spreads lips tongue long term low level exposure associated subtle symptoms including fatigue loss memory vivid dreams depression treatment research treatment mercury poisoning limited currently available drugs acute poisoning include british anti acid acid small study including construction workers exposed mercury patients treated therapy drugs resulted small fraction total estimated body mercury able increase mercury greater extent fish fish natural tendency concentrate mercury bodies form highly toxic organic compound mercury species fish high food chain shark king contain higher concentrations mercury mercury fat primarily accumulate found muscle tissue fish consumed predator mercury level accumulated fish efficient accumulating fish tissue concentrations increase time species high food chain body mercury times higher species consume process called mercury poisoning happened way japan called disease regulations international countries agreed convention mercury united_nations environment program prevent emissions convention signed 10th october united_states united_states environmental protection agency charged regulating managing mercury contamination laws authority including clean air act clean water act resource conservation recovery act safe drinking water act additionally mercury containing battery management act passed phases use mercury batteries provides efficient cost effective disposal types batteries north_america contributed approximately total global mercury emissions united_states clean air act passed mercury list toxic need controlled greatest possible extent industries release high concentrations mercury environment agreed install maximum control technologies march regulation added power plants list sources controlled instituted national cap trade system states given november impose controls legal challenge states regulations struck federal appeals court february rule deemed sufficient protect health persons living near coal fired power plants given negative effects documented study report congress newer data published showed introduction controls mercury declined sharply indicating clean air act intended impact announced new rules coal fired power plants december cement burn hazardous waste held standard standard hazardous waste united_states result source mercury pollution european_union european_union directive restriction use certain hazardous substances electrical electronic equipment mercury certain electrical electronic products limits mercury products restrictions mercury concentration packaging limit sum mercury lead batteries limit july european_union banned mercury non electrical measuring devices ban applies new devices contains health care sector year grace period manufacturers norway norway enacted total ban use mercury manufacturing import export mercury products effective january lakes norway found poor state mercury pollution excess mercury sediment norway minister environment development said mercury dangerous environmental satisfactory alternatives products available fitting induce ban sweden products containing mercury banned sweden denmark denmark banned dental mercury surface permanent adult teeth


chemical element symbol atomic number extremely radioactive synthetic element stable known half life approximately seconds created centre heavy research near city germany named periodic table block element member 7th period placed group elements chemical experiments carried confirm heavier platinum group calculated similar properties lighter platinum history discovery created november institute heavy research germany peter direction team bombarded target accelerated heavy detected single series experiments team carried reaction heavier runs convincingly detected known daughter decay properties prior failed synthesis attempts joint institute nuclear research soviet_union joint working party recognised team report naming nomenclature unnamed elements known platinum published recommendations according element called corresponding symbol systematic element element discovered discovery confirmed permanent decided widely chemical community levels chemistry classrooms advanced textbooks recommendations ignored scientists field called element symbol simply suggested team honor city element discovered team originally considered naming element suburb known element discovered eventually decided new officially recommended august detailed list information discovery individual stable naturally occurring radioactive synthesized laboratory observing decay heavier elements different reported atomic masses unconfirmed known states unconfirmed decay predominantly alpha decay undergo spontaneous stability half lives extremely unstable radioactive general heavier stable lighter stable known heaviest known half life seconds state reported longer half life minutes half life seconds respectively remaining states half lives unknown region predicted long half lives seconds discovery predicted half life seconds found half life predicted stable beta decay known observed undergo beta decay theoretical calculation quantum model experimental alpha decay half life data known magic number alpha decay half life order years exactly approach case year half life non magic predicted properties chemical eighth member series transition metals element shown transition metal expected elements form fourth transition metal series platinum group metals noble metal calculations atomic similar lighter platinum implying basic properties resemble group elements platinum prediction probable chemical properties received attention recently expected noble metal based stable states lighter group elements stable states predicted states neutral state predicted stable solutions comparison platinum known maximum state group stable states expected maximum states elements element element stable gas phase solution predicted similar properties lighter platinum having similar electronic structures expected molecular geometry predicted compounds expected behave like lighter physical atomic expected solid normal conditions body centered cubic structure unlike lighter face centered cubic structure expected different electron charge heavy metal density comparison known element density measured density results high atomic weight effects production measure quantity impractical sample quickly decay outer electron configuration calculated principle follow platinum outer electron configuration electron pair seventh period elements expected electron configurations violating principle atomic radius expected experimental chemistry determination chemical characteristics established short half lives limited number likely volatile compounds studied small scale compounds likely sufficiently volatile lighter platinum volatile analogous compound sufficiently volatile volatile possible chemical studies carried produced half life second rate production week half life stable confirmed seconds long perform chemical studies obstacle need increase rate production allow experiments carry weeks months significant results obtained separation detection carried continuously separate automated systems experiment gas phase solution chemistry yields heavier elements predicted smaller lighter elements separation techniques reused experimental chemistry received attention heavier elements rich stable promising chemical studies produced indirectly alpha decay heavier elements indirect synthesis methods favourable chemical studies rich produced directly reaction yield expected low furthermore reaction tested success recent experiments successfully synthesized indirect methods short half life long perform chemical studies


chemical element symbol atomic number neo latin ancient greek meaning lead confused lead minerals known history element discovered sense new entity mineral metals metal isolated peter jacob occur naturally free metal earth found states minerals free element metal gray cast sixth highest melting point element readily forms hard stable reason world production element steel including high strength compounds low water bearing minerals contact oxygen water resulting compounds world production element high pressure high temperature applications bearing far common breaking chemical bond atmospheric molecular nitrogen process biological nitrogen known bacteria animals involved nitrogen contain form different contain fully vital organisms essential element life higher organisms bacteria characteristics physical properties pure form grey metal melting point naturally occurring elements carbon higher melting points weak starts lowest thermal expansion commercially metals strength wires increases times diameter decreases known ranging atomic mass nuclear seven occur naturally atomic masses naturally occurring unstable abundant comprising half life undergoes double beta decay mass numbers half lives approximately unstable decay noted common application involves product parent short lived gamma daughter nuclear imaging applications medicine university technology applied patent based production compounds chemistry transition metal scale standard atomic weight visibly react oxygen water room temperature bulk occurs temperatures resulting volatile high temperatures prevents formation continuous protective layer stop bulk metal states stable table left chemistry compounds similarity instability iii iii compounds example contrasts stability iii compounds highest state seen normal compound strong water forming weaker similar tendency form complex lower values incorporate forming dark blue containing detection broad range states reflected yellow solid iii dark red solid black solid dark green solid brown solid structure clusters charge like transition metals forms quadruple bonds compound transformed quadruple bond state possible carbon history principal ore extracted previously known confused utilized like surface solid distinguishable confused common lead ore pbs called comes ancient greek meaning lead greek word proposed languages reportedly deliberately steel 14th century japanese sword art employed widely later lost west examined sample determined contain lead swedish chemist stated firmly instead correctly proposed ore distinct new element named mineral resided isolated peter jacob successfully isolated carbon oil century industrial use relatively scarce pure metal difficult extract necessary techniques immature early steel showed great promise increased efforts manufacture large scale hampered inconsistent results tendency william filed patent rendering leading applications heating element high temperature support light formation degradation require physically sealed held gas frank developed process recover remains primary isolation process world war demand armor plating substitute high speed british tanks protected steel plating proved ineffective steel plates replaced lighter steel plates allowing higher speed greater better protection germans steel heavy artillery like super heavy big traditional steel temperatures produced ton shell war demand advances allowed extensive development peacetime applications world war saw strategic importance substitute steel occurrence production 54th abundant element earth crust 25th abundant element oceans average parts billion 42nd abundant element universe russian mission discovered bearing grain fragment taken mare moon comparative rarity earth crust offset concentration number water combined way copper found found minerals main commercial source mined principal ore recovered copper mining world production tonnes largest producers china united_states chile peru mexico total reserves estimated million tonnes concentrated china chile continent world production evenly shared north_america south_america mainly chile china europe rest asia armenia russia iran produce remainder processing ore air temperature process gives ore usually extracted copper completely remove solution precipitated hydrogen converts isolated solid heating solid gives crude metallic produced reduction hydrogen steel production reduced reaction addition iron produce common form contains value approximately august maintained price near reached peak june london metal exchange announced traded exchange history mining historically southern norway opened dedicated closed reopened year produces kilograms long tons short tons year large mines colorado henderson climax british_columbia yield primary product copper deposits canyon utah northern chile produce copper mining applications produced rest chemical applications estimated global use structural steel steel chemicals tool high speed cast iron metal withstand extreme temperatures significantly expanding making useful environments intense heat including military armor aircraft parts electrical contacts industrial motors high strength steel example contain small portions tonnes year tool cast high temperature valued steel high resistance contributes resistance specifically especially called increases strain increasing energy required dissolve iron surface enhance resistance example grade example lower density stable price place example series high speed steel series contain flame resistant coating metals melting point rapidly temperatures making better suited use vacuum environments resisting temperatures twice strength pure tests resisted standard salt salt salt hours little difficult measure based contain iron limited applications example resistance pure pump come contact applications pure element powder plants power plants pollution controls element acts catalyst form molecules detection infrared light replace certain low voltage ray sources specialized uses radioactive generate medical imaging compounds global use solid high pressure high temperature agent forms strong films metallic surfaces common event catastrophic failure thin layer prevents contact parts properties distinct advantages traditional electronics applications catalyst petroleum containing nitrogen oxygen electrically conducting primary use heating elements operating temperatures air metals lead precipitated lead lead bright orange pigment based mixed versatile chemical industry examples selective acid suitable process direct selective acid researched biological coated lime glass solar cells acid stain thin layer parent daughter medical procedures handled stored biological role important role living organisms metal active site certain nitrogen involved terminal step reducing molecular nitrogen usually contains active site replacement iron known structure center similar iron proteins incorporates multiple clusters reaction perform formula electron transport chain nitrogen reduced free hydrogen gas energy process requiring splitting plus free evidence reported earth early oceans limiting factor nearly billion years evolution life includes plants animals chain follows relative lack oxygen early ocean resulted dissolved compounds low water forms containing minerals contact oxygen water lack dissolved limited growth nitrogen fixing bacteria require bearing process lack nitrogen fixing bacteria limited growth ocean require nitrogen suitable production organic nitrogen compounds like proteins bacteria oxygen created limited reacted water minerals sea produce making available nitrogen fixing bacteria bacteria provided fixed usable nitrogen compounds higher forms life suggested production mars life transported earth billion years ago oxygen promoted nitrogen making available water directly earth ancient history oxygen arrived large quantities earth air water organisms continued fix nitrogen conditions isolated protected nitrogen fixing oxygen equivalent structures structural isolation nitrogen reactions organisms continues present forms compounds organic molecules including transported human body containing known bacteria number increasing year include animals humans acid process containing activity directly proportional body extremely high concentration trend act processes concentration affects protein synthesis growth animals plants compound called despite contains reacted form complete containing called ancient discussed fix nitrogen bacteria far identified use state similar plants animals reduction certain small molecules process regulating nitrogen carbon human intake trace element necessary survival humans mammals studied dependent known based active site mitochondrial people severely poorly functioning prone toxic reactions foods human body contains kilogram body weight higher concentrations liver lower present human tooth help prevent decay average daily intake varies depending content food pork lamb beef liver approximately parts million significant sources include green beans eggs seeds wheat flour grain acute seen humans depends strongly chemical state studies rats median lethal dose low compounds human data unavailable animal studies shown chronic day cause growth low birth weight affect lungs liver competitive reduces concentration tissues low soil concentration geographical band northern china iran results general associated increased rates cancer compared united_states greater supply soil people living areas times greater risk cell reported consequence non supplemented total nutrition complete feeding long periods time results high blood levels way presumably pure cause occurs primarily adults consequences marked cases related diseases disease seen inability active site known human use resulting results high levels damage copper high levels interfere body copper producing copper prevents proteins binding copper increases copper consume high levels suffer growth loss fur pigment symptoms copper injection effective copper aggravated excess copper reduction deliberately induced purposes compound bright red copper agent treatment copper animals introduced treatment wilson disease hereditary copper disorder humans acts competing copper absorption increasing found effect potentially membrane process dependent copper promising avenue investigation treatments cancer age related diseases involve blood vessels precautions generated mining toxic especially including dust trapped later low levels prolonged exposure cause eyes skin direct avoided regulations specify maximum exposure hour day chronic exposure cause symptoms including fatigue joint pains levels immediately dangerous life health


chemical element symbol atomic number previously known comes villain greek mythology rare hard blue gray transition metal highly resistant metals group widely minor components chemical makes valuable substance laboratory equipment substitute platinum main use today electronic equipment mobile phones dvd players video game systems computers similar occurs minerals mix history discovered sweden year earlier charles discovered element english chemist william compared derived density density concluded despite difference measured density identical decided friedrich confirmed results thought element conclusion disputed german chemist rose argued additional elements sample named children goddess tears supposed element later identified mixture found identical discovered differences demonstrated christian claire louis determined compounds confirmation came swiss chemist jean charles proved elements discoveries stop scientists publishing articles called produce metallic form reduced heating atmosphere hydrogen early investigators able produce relatively pure metal produced von wires metallic light replaced widespread use derived mythological father greek mythology story punished death condemned stand knee deep water perfect fruit growing head bent drink water drained level reach reached fruit branches moved grasp wrote metal partly allusion immersed acid absorb saturated decades commercial technology separating involved potassium away potassium process discovered jean charles method supplanted extraction containing solutions characteristics physical properties dark blue gray dense hard easily fabricated highly heat electricity metal renowned resistance fact temperatures completely immune attack normally aggressive regia dissolved acid acidic solutions containing solution potassium high melting point boiling point exceeded elements metals carbon exists phases alpha beta alpha phase relatively soft body centered cubic structure space group constant electrical beta phase hard crystal symmetry space group electrical relatively high beta phase converts alpha phase heating bulk entirely alpha phase beta phase usually exists thin films obtained chemical deposition deposition salt solution chemical properties forms states stable state seen starting material compounds compounds created basic solutions melting metal examples occur instead formula represents form dimensional framework contains lone groups separation forms compounds states type tax tax tax multi core complexes compounds known white solid melting point white solid melting point water additional elevated temperatures forming black highly obtained reduction hydrogen exist forms compounds states low reported cases metals hardest known compounds stable like commonly hard cutting tools iii thin film processes los national laboratory united_states developed composite material hardest materials synthesized korean researchers developed copper flexible times stronger commonly steel stable reflective proposed use infrared wave mirrors natural consists stable denotes state predicted decay ways transition ground state beta decay electron capture nuclear observed lower limit half life years set ground state half life hours naturally occurring nuclear excluding short living universe taking account abundance abundance natural mixture excluding short living examined theoretically material nuclear weapons better known hypothetical material external shell intensive high energy hypothetical exploding nuclear weapon radioactive half life days produces gamma rays approximately million electron volts energy apiece significantly increase nuclear fallout explosion months weapons built tested far publicly known certainly weapons target material accelerated beams production short lived including occurrence estimated earth crust weight species minerals far industry raw materials important mineral extraction mineral structure called called high density containing minerals makes use separation best method minerals include primary mining australia largest producer global advanced metals known minerals operates mines western_australia southwest region reopened january mining site suspended global financial crisis year reopened global advanced metals announced demand factors mining operations cease end february produces primary concentrate upgraded operation sold customers large scale producers brazil canada ore yields small percentage countries china higher percentage produce significant percentage world output produced thailand malaysia product tin mining separation deposits found small percentage included tin contains economically useful amounts world production undergone important geographic shift start 21st century production predominantly australia brazil beginning major sources production mines dramatically shifted african countries future sources supply order estimated size explored saudi_arabia egypt greenland china canada australia united_states finland brazil estimated years left resources based extraction current rates demonstrating need increased recycling status conflict resource considered conflict resource industrial mineral extracted found central africa linked warfare democratic republic according october united_nations report smuggling helped fuel war crisis resulted approximately million deaths making world deadliest documented conflict world war ethical questions raised responsible corporate behavior human rights wildlife exploitation resources armed conflict regions basin important local economy contribution mining world supply usually small united_states geological survey reports region produced little world output peaking stated aim solutions hope project source conflict free democratic republic production steps involved extraction mineral crushed concentrated gravity separation generally carried near site chemical contain significant amounts valuable metal metals extracted sold overall process large number chemical treatment procedures breakdown primary sources developed adopted commercial production tested fairly large scale tested laboratory scale processes essentially divided reduction metallic compound form reduction reactions fusion acid dissolution extraction begins step ore treated acid acid produce water hydrogen allows metals separated non metallic rock hydrogen removed solution liquid liquid extraction organic step allows simple removal metal iron remain phase form separation achieved adjustment requires higher level remain organic phase removed extraction acidic water pure hydrogen solution alternatively treated potassium produce potassium produce metallic reduction approximately salt older method called process separated treating initial mixture hydrogen potassium resulting potassium separated different water modified version hall process instead requiring input output metal liquid form operates non liquid initial discovery came cambridge_university researchers immersed small samples certain salt reduced electric current uses metal carbon salt capacity supply annual global demand atmosphere order shield contamination atmospheric gases grinding difficult especially condition extremely readily formed metal sheets applications electronics major use metal powder production electronic components mainly high power exploit tendency form protective surface layer powder pressed shape plate solution solid plate layer thin thinner similar layer instance aluminium high achieved small volume size weight advantages attractive portable personal computers automotive electronics produce variety high melting points strength metals making tools equipment production jet engine components chemical process equipment nuclear missile parts drawn fine wires metals aluminium attack body widely making surgical instruments example construction ability form direct bond hard tissue acid hot acid hot solutions cause property makes useful metal chemical reaction vessels pipes heat exchanging steam heating acid extensively production ultra high frequency electron tubes radio capable capturing oxygen nitrogen forming helps sustain high vacuum needed tubes uses high melting point resistance lead use metal production vacuum parts extremely formed variety resistant parts valve bodies high density shaped charge formed liners constructed greatly increases armor penetration capabilities shaped charge high density high melting point occasionally precious watches highly material high makes necessary use highly foam lower hip replacement avoid stress non non magnetic metal considered acceptable patients undergoing procedures special high index glass camera lenses precautions compounds containing rarely encountered laboratory metal highly body attention focused elements physical nature chemical compound people exposed workplace breathing skin contact eye contact safety health administration set legal limit exposure limit exposure workplace hour national institute safety health set recommended exposure limit hour short term limit levels immediately dangerous life health


synthetic chemical element chemical symbol atomic number named honor lawrence inventor device discover artificial radioactive elements radioactive metal eleventh element final member series like elements atomic number produced particle bombarding lighter elements charged particles currently known stable half life hours shorter lived half life minutes commonly chemistry produced larger scale new half life hours reported confirmed chemistry experiments confirmed heavier periodic table element classified 7th period transition metals electron configuration position periodic table having configuration instead configuration means volatile expected position periodic table comparable lead 1950s 1960s 1970s claims synthesis varying quality laboratories soviet_union united_states priority discovery naming element disputed soviet american scientists international union pure applied chemistry established official element gave american team credit discovery giving teams shared credit discovery changing element history scientists lawrence berkeley national laboratory claimed discovery element called time attempted element bombarding target follow experiment performed target destroyed eighteen tracks noted decay energy half life berkeley team noted cause production element possibilities ruled data agrees reasonably later discovered alpha decay energy half life evidence obtained experiment fell far short strength required demonstrate synthesis element later lawrence berkeley laboratory attempted element bombarding results experiment conclusive important work element carried berkeley nuclear physics team albert robert workers february reportedly produced bombarding target consisting element heavy linear berkeley team reported detected manner decayed alpha particle half life identification later corrected later work proved properties detected considered time convincing proof synthesis element mass assignment certain proved mistaken affect arguments favor element having synthesized scientists joint institute nuclear research soviet_union raised criticisms answered adequately exception common target reactions produced expected likely lead narrow yield curve broad reported berkeley team possible explanation low number events attributed element important intermediate step discovery element evidence completely convincing berkeley team proposed symbol orlando lawrence inventor commission nomenclature chemistry accepted changed symbol acceptance discovery later characterized hasty team work element came reported created bombarding identifying indirectly granddaughter half life reported somewhat high possibly background events later work reaction identified decay energies ranges assigned despite repeated attempts unable confirm assignment alpha half life seconds russians proposed new element later element experiments berkeley demonstrated chemistry new element known group reported synthesis half life alpha decay energy nuclear physics team university california berkeley successfully performed series experiments aimed measuring nuclear decay properties mass numbers previous results berkeley confirmed apart berkeley group initial erroneous assignment produced instead probably correct final doubts finally energies rays emitted measured granted discovery lawrence berkeley laboratory ideal data element existence trans working group officially recognized nuclear physics teams berkeley concluding berkeley experiments important step discovery completely convincing experiments came close needed level confidence taken berkeley experiments clarified confirmed previous observations finally resulted complete confidence discovery element use long time point retained august international union pure applied chemistry ratified symbol meeting geneva characteristics physical final member series considered group element filled shell expected resemble 7th period transition metals periodic table located right left transition metal shares physical chemical properties expected solid normal conditions assume close packed crystal structure similar lighter known estimated close value strongly suggesting metallic prediction supported systematic values heat bulk atomic volume neighboring elements specifically expected metal easily air steam having atomic volume similar metallic radius expected heavy metal density predicted melting point far value chemical devised concept elements formed series series elements predicted element final member stable solution decades later element finally synthesized prediction confirmed studies element showed reacted form product likely found similar chemical studies performed comparing elements found short half life confirmation ahead sequence occurs solution compounds similar example iii water radius smaller ahead later experiments longer lived confirmed roughly place found radius larger expected simple periodic trends later experiments refined value calculated value pointed end series larger analogous exception cause speculated effects speculated stabilized reducing conditions electron leading experiments reduce solution unsuccessful basis standard potential couple calculated indicating existence solution unlikely upper limit couple predicted values predicted stability group state transition series highest decreases atomic act predicted ground state electron configuration ground state term symbol following principle configuration lighter year calculations published questioned prediction instead expecting configuration early calculations gave conflicting results recent studies calculations confirm suggestion calculations concluded energy difference configurations small uncertain ground state later calculations concluded configuration favored spherical nearest atomic nucleus quickly mass increases significantly team scientists led calculated metal sources differ depending electron configuration feasible carry experiments exploit fact measure electron configuration configuration expected volatile configuration similar block element lead results inconclusive evidence volatile obtained lower limit platinum significantly higher estimated value configuration electron configuration unknown energy measured measured value agreed theoretical prediction provided step measuring energies value lowest supports configuration electron expected weakly bound suggests behave similarly block elements true heavier instead behave similarly metals potassium ways given configuration correct regarded transition metal definition element incomplete sub shell rise incomplete sub shell unlike lighter group elements classified known mass numbers radioactive additionally nuclear known mass number longest lived half life hours longest lived known date suggesting shore island stability shorter lived usually chemical experiments currently produced final decay product heavier harder elements discovered decay chain half life seconds chemical studies currently slightly longer lived half life minutes usually purpose longest lived min min known half lives seconds shortest lived half life mass numbers expected longer half lives half lives increase smoothly dip preparation heaviest produced alpha decay products middle produced bombarding targets light neon important range produced bombarding producing produced bombarding producing alpha particle half lives short allow complete chemical process early experiments rapid extraction agent dissolved organic phase phase solutions different charge extract organic phase different ranges method separate identified emitted alpha particles recent methods allowed rapid selective place time separate longer lived removed catcher foil acid


synthetic chemical element symbol atomic number named honor alfred nobel inventor dynamite science radioactive metal tenth element penultimate member series like elements atomic number produced particle bombarding lighter elements charged particles total known exist stable half life minutes shorter lived half life minutes commonly chemistry produced larger scale chemistry experiments confirmed heavier periodic table chemical properties completely known known solution discovery predicted stable state state characteristic predictions later confirmed state stable state solution difficult state 1950s 1960s claims discovery laboratories sweden soviet_union united_states swedish scientists soon retracted claims priority discovery naming element disputed soviet american scientists international union pure applied chemistry established official element credited soviet team discovery discovery discovery element complicated process claimed groups sweden united_states soviet_union complete report detection came joint institute nuclear research soviet_union announcement discovery element announced nobel institute sweden team reported bombarded target hours half hour intervals exchange chemistry performed target contained samples alpha particles drops earlier atomic number half life reported minutes assigned possibility alpha particles observed presumably short lived created electron capture element excluded team proposed new element immediately approved decision group later characterized hasty following year scientists lawrence berkeley national laboratory repeated experiment unable find events background effects swedish team attempted explain berkeley team inability detect element maintaining discover later work shown lighter heavier produced swedish experiments half life minutes exist swedish team results likely half life minutes quickly undergoes triple alpha decay decay energy hypothesis lent weight fact easily produced reaction separated chemical methods later work showed state stable samples alpha particles contained swedish team later retracted claim associated activity background effects berkeley team consisting albert john claimed synthesis element team new heavy linear bombard target unable confirm activity claimed instead able detect supposedly daughter produced apparent half life later work confirmed produced reaction half life actually berkeley team attempted defend work stating found half life measurements actually related granddaughter produced abundant energy differences attributed resolution drift problems previously reported influenced results experiments showed second half life work showed easily produced transition half life formed reaction energy given probable actually produced experiment team continued studies claimed able produce decayed predominantly alpha particle half life associated spontaneous branch activity initially assigned later changed noted certain produced difficult conditions berkeley team decided adopt proposed swedish team element experiments carried aiming element experiment bombarded alpha energies observed assigned team wrote formation lead produce ruled later experiments noted new produced mercury lead scientists stood conclusion element produced reaction mentioning half life seconds decay energy later experiments proved background effects experiments lowered decay energy values high possibly match team later stated results conclusive berkeley scientists claimed discovery element reaction carbon claimed production claimed synthesized alpha decaying element half life alpha decay energy assigned giving reason assignment values agree known agree known probably played experiment discovery inconclusive work element continued experiments carried detect alpha decay daughters element element reaction target neon products carried silver catcher foil detected yield interpreted evidence parent synthesized noted produced directly reaction simultaneous alpha particle excess steps taken ensure directly catcher foil half life detected higher modern value experiments conducted reactions finding half life time value earlier berkeley value understood later work proved formation likely experiments berkeley ones results probably correct considered conclusive detection element convincing experiment came reactions concluded half life longer seconds claimed berkeley later work berkeley oak ridge national laboratory fully confirmed discovery element clarified earlier observations december berkeley group repeated experiments fully confirmed data finally assign correctly previously synthesized identify time claimed discovered team carried chemical experiments element concluded behaved heavier russian scientists proposed new element recently died creating element naming controversy resolved decades group proposed names working group claims discovery concluded work correctly detected assigned atomic number time team officially recognised possible detected berkeley decision criticized berkeley following year calling reopening cases elements futile waste time agreed decision attempted resolution element naming controversy ratified names elements element ratified basis entrenched literature course years alfred nobel commemorated fashion outcry names respect choices comment period ensued named element new proposal eponymous laboratory nuclear reactions proposal accepted restored today symbol refers element characteristics physical periodic table located right left metal prepared bulk quantities bulk preparation currently impossible number predictions preliminary experimental results properties metallic state exist metals configurations configurations examined measured predicted values cohesive energies metallic metals conclusion increased binding energy configuration configuration compensate energy needed promote electron true late expected metals prediction confirmed increasing state series concludes attributed increases increasing atomic number effect predominantly instead unlike metal estimated value close values supporting theory form metal like late metallic assume face centered cubic crystal structure metal metallic radius melting point predicted value estimated neighboring element density predicted chemical chemistry characterized known solution states stable largely expected discovery solution behave like state predominant predicted state relatively stable ground state electron configuration including stable filled shell took nineteen years prediction confirmed experiments conducted compare chemical behavior elements reacted resulting deposited tube carried gas found produced strongly solid surfaces proving volatile like investigated elements expected exhibit behavior experiment inconclusive preferred state determination favoring state wait year exchange experiments carried thousand finding behaved differently like earth metals proved solution stable state strong absent later experimentation showed earth metals ability similar complexes weakly ability solution calcium somewhat closer standard reduction potential couple estimated positive value shows stable good agent quoted values vary sources accepted standard estimates predicted value couple energies formation estimated respectively atomic act expected arranged configuration ground state term symbol experimental electron configuration forming compounds lost leaving core trend set electron configurations state likely lost leaving stable core filled shell potential measured based assumption ones value refined high radius estimated respectively radius found significant figures calculated known mass numbers radioactive additionally nuclear known mass numbers longest lived half life minutes longest lived half life seconds predicted longer half life min additionally shorter lived half life minutes chemical experimentation produced larger quantities stable half life minutes seconds seconds seconds seconds remaining half lives second shortest lived known half life especially interesting theoretically middle series formation nuclear known controlled come spherical shell half lives increase smoothly dip appears half lives drop sharply spontaneous dominant decay mode example half life seconds shows mutual poses limit island relative stability long lived series odd continue longer half lives mass numbers increase dip trend preparation produced bombarding targets exception produced daughter commonly produced bombarding method common target second minutes produce produced separated similar way neighboring momentum produced bring physically far away target produced bringing thin foil metal usually aluminium platinum gold target vacuum usually combined trapping gas atmosphere frequently carrying gas jet small opening reaction chamber long tube including potassium gas transported tens meters thin layer collected foil removed acid completely foil isolated exploiting tendency form state unlike typically conditions acid stationary organic phase acid mobile phase acid exchange columns pass column remain column direct catcher gold foil process complicated need separate gold exchange extraction columns


chemical element symbol atomic number thirteenth element series like common state seen compounds solution like compounds late compounds form complexes water molecules swedish chemist separated rare earth previously unknown components called respectively relatively pure sample metal obtained second abundant found trace quantities earth easily metal bright gray fairly soft slowly air despite high price rarity radiation source portable ray devices solid state significant biological role particularly toxic properties physical properties pure metal bright exposure air metal cut knife major stable chemical properties slowly air burns readily form iii slowly cold water quickly hot water form reactions slow room temperature vigorous white yellow white yellow readily acid form solutions containing pale green iii exist complexes metallic non metallic elements forming range compounds including compounds exhibits states state common state observed solutions exists solution state surrounded molecules water exhibit bright blue known called reddish purple compounds reduction iii compounds examples compounds include compounds green greenish white vigorously water reaction results hydrogen gas exhibiting fading reddish color combination results hydrogen produce hydrogen gas acid yields range primary decay mode abundant stable electron capture primary mode beta primary decay products element primary products element longest lived abundant thought stable predicted undergo alpha decay long half life longest lived half life years half life days half lives minutes thirty nuclear detected lighter atomic mass units decay electron capture beta plus decay exhibit significant alpha decay heavier undergo beta minus decay history discovered swedish chemist looking rare earth elements method earlier discover rare earth elements started removing known additional processing obtained new substances brown green brown substance element named green substance unknown element named element ancient greek place associated scandinavia iceland atomic symbol changed rare early workers sufficiently actually green color content observing strengthening characteristic absorption bands progressively removed researcher obtain nearly pure charles james british working large scale new_hampshire college durham reported results having discovered method famously needed operations establish material high purity offered commercially late 1950s result adoption exchange separation technology chemical division american chemical corporation offered grades purity price kilogram period purity second highest occurrence element found nature pure form found small quantities minerals rare found minerals containing particular occurs mineral occurs minerals abundance earth crust weight parts billion makes approximately parts million soil value range parts million makes parts solar system exists concentrations parts weight ore occurs commonly china australia brazil greenland india united_states large reserves total reserves approximately tonnes abundant earth production principally extracted found river sands exchange newer exchange extraction techniques led easier separation rare yielded lower costs production principal sources today southern china thirds total rare earth content tied rarity metal isolated reduction metal calcium reduction closed container natural compounds commercially important approximately tonnes year produced cost metal powder cost applications despite rare expensive applications laser triple aluminum active laser medium material high efficiency widely military applications medicine single element operate based efficient superficial tissue minimal depth air water makes attractive laser based surgery ray source despite high cost portable ray devices use bombarded nuclear radiation source sources useful life year tools medical dental diagnosis detect defects inaccessible mechanical electronic components sources need extensive radiation protection small cup lead gaining popularity ray source cancer treatment half life days major lines comparable intensity popular use industrial high temperature similarly potentially use magnetic materials microwave equipment similar arc lighting unusual spectrum case green lines covered elements blue color exposed light euro measure blue calcium personal visual monitoring radiation biological role precautions small human body exact unknown observed biological role small amounts stimulate mildly toxic completely injected cause liver cause concentration liver damage prevalent male mice female mice despite low level humans occurs highest amounts liver bones humans typically consume year roots plants dry weight vegetables usually contains billion dust powder toxic cause explosions radioactive cause radiation poisoning


radioactive chemical element symbol confused group atomic number discovered non radioactive element isolated observed isolated gave series group similar elements periodic table soft white radioactive metal rapidly oxygen moisture air forming white coating prevents assumes state nearly chemical compounds found traces half life years predominantly beta alpha particles beta active half life hours natural ore contains natural contains close similarity physical chemical properties makes separation ore impractical instead element prepared amounts nuclear owing high price significant industrial use current applications include source agent radiation therapy targeting cancer cells body history louis french chemist announced discovery new element separated left marie extracted described substance similar similar friedrich independently discovered substance similar called comparison substances half lives determined brooks chosen new element retained articles published 1970s later suggest results published conflict reported led authors advocate credited discovery vision scientific discovery proposed suggests criticism early publications nascent state highlighting claims original papers notes contend substance contain considered vast majority historians lost interest element left topic hand credited preparation pure identification atomic number originates ancient greek meaning beam ray symbol compounds properties soft white radioactive metallic element estimated shear similar lead owing strong dark pale blue light originates surrounding air emitted energetic particles similar chemical properties elements difficult separate extraction commonly separation element gave group group elements diverse charles proposed significant change periodic table recognition introducing suggested rapidly oxygen moisture air forming white coating exists state solutions state originates electronic configuration easily donated stable closed shell structure noble gas rare state known chemical compounds limited number compounds known including similar corresponding compounds contain state particular analogous compounds differ percent space group number number formula units unit cell density measured directly calculated parameters obtained heating vacuum crystal rare earth metals produced solution solid reaction reaction carried room temperature adding acid solution containing method metal treated hydrogen platinum setup treating yields easily obtained burning air hour similar treatment yields results melting initial product obtained reacting carbon temperatures similar prepared contrast synthesized solution acid reaction aluminium yields treating results compounds obtained reduction potassium structure analogy corresponding source hydrogen reaction uncertain mixing solution acid yields white colored heating hydrogen minutes results black possibly produced acting mixture hydrogen carbon naturally occurring composed radioactive radioactive family granddaughter mainly beta small energy cases alpha particle readily identified alpha thirty identified stable half life years half life days half life hours remaining radioactive half lives hours majority half lives shorter minute shortest lived known half life alpha decay electron capture known states significant chemistry comes decay products half year according year half life beta alpha particles successive decay products series owing low available amounts low energy beta particles maximum low intensity alpha radiation difficult detect directly traced decay products range atomic weight occurrence synthesis found traces ore contains contain member series decay chain begins parent ends stable lead member series decay chain begins parent ends stable lead present series decay chain beginning ending near stable chain existed early solar system short half life low natural concentration close similarity physical chemical properties abundant bearing render separation ore impractical complete separation achieved instead prepared amounts nuclear formula reaction yield weight capture resulting small amounts synthesis separated products decay nuclear fusion lead extraction performed solution solution radiation products certain element achieved adjusting alternative procedure exchange appropriate acid result separation factor stage process separated ratio low cross linking exchange acid produced artificially institute elements germany george hospital sydney rare potential applications radiation therapy efficiently produced bombarding target reaction yields half life hours metal prepared reduction vacuum temperature higher temperatures resulted product lower ones lead incomplete transformation chosen metals volatile applications owing high price currently significant industrial use highly radioactive studied use active element generators example spacecraft pressed efficient source activity exceeding standard pairs applications beta source merely generates alpha decay captures alpha particles owing large cross section nuclear reaction formula sources applied probe standard device measuring quantity water present soil moisture density quality control highway construction logging applications investigations applied medicine produce generator agent radiation therapy particular targeted alpha therapy half life days makes suitable radiation therapy half life minutes decay products alpha particles kill cancer cells body major difficulty application injection simple complexes resulted accumulation bones liver period tens years result cancer cells quickly killed alpha particles radiation decay products induce new solve problem bound agent acid acid reduced accumulation bones body remained slow better results obtained agents acid acid coupled delivery combination tested mice proved effective breast medium half life years makes convenient radioactive modeling slow vertical mixing oceanic waters associated processes studied required accuracy direct measurements current order meters year evaluation concentration depth profiles different allows estimating mixing rates physics method follows oceanic waters contain dispersed decay product gradually concentration increases depth stays nearly constant concentration follow depth profile instead increases sea occurs mixing processes raise additional sea analysis depth profiles allows model mixing behavior precautions highly radioactive experiments carried specially designed laboratory equipped glove box administered rats deposited bones liver comparable slightly lower


synthetic element chemical symbol atomic number metallic radioactive element series element currently produced quantities bombardment lighter elements ninth element produced particle bombarding lighter elements charged particles total sixteen known stable half life days shorter lived half life hours commonly chemistry produced larger scale discovered bombarding alpha particles method produce today named father periodic table chemical elements available quantities million produced hour chemistry typical late state accessible state owing small amounts produced having relatively short half lives currently uses outside basic scientific research discovery ninth element synthesized synthesized albert gregory bernard harvey team leader stanley thompson early university california berkeley team produced half life minutes bombarded target consisting billion alpha particles berkeley radiation laboratory inch increasing target atomic number element synthesized time total seventeen produced discovery program begun heavier method necessary previous method elements capture work lack beta decaying produce element short half life spontaneous constituted hard limit success capture process predict production possible team use rough calculation number produced approximately equal product number target material target cross section beam intensity time bombardment factor related half life product bombarding time order half life gave experiment conditions preparation element experiment expected calculation demonstrated feasible ahead experiment target material produced readily year billion week half life meant element experiments conducted week produced separated target necessary upgrade obtain needed intensity alpha particles second applied necessary funds applied funding harvey worked target focused methods chemical isolation suggested acid separate lighter actual synthesis technique introduced albert technique placed opposite target beam momentum leave target caught catcher foil gold target technique developed alfred technique gave high yield absolutely necessary working rare valuable product target material target consisted deposited thin gold foil bombarded alpha particles berkeley high beam density particles second area cm2 target cooled water liquid foil replaced initial experiments carried september alpha decay seen suggested decayed electron capture experiment repeated search instead spontaneous events repetition experiment happened february day discovery february alpha target occurred hour sessions university california campus radiation laboratory hill deal situation complex procedure took catcher targets harvey use regia dissolve pass exchange column separate elements gold products resultant drops entered test tube took car radiation laboratory soon possible thompson exchange column acid solution drops collected platinum dried heat lamps expected contain respectively new elements finally placed connected spontaneous events recorded huge showing number time direct detection observation spontaneous events arising electron capture daughter identified followed double triple fourth eventually officially proved chemical identification element total reported till notified team left sleep additional analysis experimentation showed produced mass decay electron capture half life thought fitting element named russian chemist developed periodic table nearly experiments discovering elements depended method predicting chemical properties based element position table middle cold war naming element russian somewhat bold gesture sit american critics second chemical elements decided element named russian chemist father periodic table fact discovery came cold war request permission government united_states propose element named russian granted accepted international union pure applied chemistry symbol changed general_assembly paris characteristics physical periodic table located right left metal prepared bulk quantities bulk preparation currently impossible number predictions preliminary experimental results properties metallic state exist metals configurations configurations examined measured predicted values cohesive energies metallic metals conclusion increased binding energy configuration configuration compensate energy needed promote electron true late expected metals increasing state series concludes attributed increases increasing atomic number studies trace quantities confirmed prediction gibson estimated metal metal metallic radius like late metallic assume face centered cubic crystal structure melting point estimated value predicted neighboring element density predicted chemical chemistry known solution states state reported confirmed discovery predicted predominantly solution behave similarly synthesis predictions confirmed observation discovery sequence exchange column later observation form exchange extraction studies led conclusion radius somewhat smaller previous form coordination complexes acid reducing conditions iii easily reduced stable solution standard reduction potential couple variously estimated comparison behavior compared reported produced russian scientists obtained reducing higher states found stable neutral water solution later experiments found evidence found behaved like elements reduced like metals russian team conducted studies metal concluded formed form mixed crystals elements status state tentative predicted suggesting iii easily experiments strong agent unable iii atomic act expected arranged configuration ground state term symbol experimental electron configuration forming compounds lost leaving core trend set electron configurations state potential measured based assumption ones value refined high radius estimated calculations based trend distribution radius produced value radius radius sixteen known mass numbers radioactive additionally nuclear known longest lived half life days longest lived half life minutes slightly shorter lived half life hours chemical experimentation produced larger quantities alpha particle stable half life days half life hours half life hours half life hours remaining half lives hour majority half lives minutes half lives increase smoothly onwards reaching maximum experiments predictions suggest half lives decrease apart half life days spontaneous dominant decay mode mutual posing limit island relative stability long lived series important electron capture time alpha decay time easily detected spontaneous electron capture daughter presence undergo spontaneous alpha characteristic energies provide useful identification production isolation produced bombardment targets heavy slightly heavier ones produced bombarding targets lighter carbon nitrogen important stable range produced bombardment alpha particles produced daughter produced transfer reaction typically commonly produced bombarding alpha particles preferred available longer half life target longer available quantities quantities produced momentum produced bring physically far away target produced bringing thin foil metal usually aluminium platinum gold target vacuum need immediate chemical separation costly prevents expensive target trapped gas atmosphere frequently gas jet small opening reaction chamber carries long tube including potassium gas transported tens meters analyzed quantity determined separated foil material products applying acid foil exchange column solution saturated acid acting foil gold thin simply dissolve gold regia separating gold exchange acid finally separated selective exchange column gas jet method renders steps unnecessary procedure commonly separation elements possible way separate extraction acid abbreviated stationary organic phase acid mobile phase sequence reversed exchange column heavier later separated method advantage free organic agent compared column disadvantage late sequence method exploits distinct properties initial steps employs extraction instead added reduce state acid mercury extraction proceeds remain column stays acid state hydrogen isolated selective acid remove including finally acid remove possible use column acid reducing iii like earth metals chemical isolation achieved volatile analogous compound known volatile