chemical element symbol atomic number radioactive noble gas occurring naturally decay product stable half life days substances remains gas normal conditions gas normal conditions stable considered health hazard intense hindered chemical studies compounds known formed intermediate step normal radioactive decay chains slowly decay lead common radioactive elements earth earth formed naturally occurring long half lives order years decay product decay product continue occur tens millions years concentrations produces radioactive elements called known daughters decay products unlike daughters stick surfaces dust particles air contaminated dust particles stick lung increase risk developing lung cancer unlike intermediate elements aforementioned decay chains easily naturally occurring responsible majority public exposure radiation single largest contributor individual background radiation dose variable location location despite short lifetime gas natural sources accumulate far higher normal concentrations buildings especially low areas crawl spaces density occur water water comes ground source spring waters hot springs studies shown clear link breathing high concentrations lung cancer considered significant affects indoor air quality worldwide according united_states environmental protection agency second frequent cause lung cancer cigarette smoking causing lung cancer deaths year united_states deaths occur people smoked second frequent cause lung cancer number cause non according estimates characteristics physical properties gas human senses standard temperature pressure forms gas density times density earth atmosphere sea level gases room temperature noble gases standard temperature pressure cooled freezing point brilliant turns yellow orange red temperature intense radiation produces water lighter noble gases organic water chemical properties noble gas day half life makes useful physical sciences natural member zero elements called noble gases common chemical reactions outer shell contains produces stable minimum energy configuration outer tightly bound required extract electron shells known energy accordance periodic trends lower element period early studies concluded stability order dioxide significantly higher stability hydrogen cost experimental chemical research seldom performed result reported compounds powerful agents forming elements temperature low thought short half life compounds possible study compound detail theoretical studies predict bond distance compound stable volatile lighter counterpart predicted lower formation higher claimed calculated stable doubtful synthesized believed form following reaction reported compounds confirmed predicted stable linear molecular geometry molecules found significantly stabilized spin orbit inside proposed drug despite existence viii viii compounds claimed exist highly unstable unstable predicted stable viii compound analogous instability viii shell known pair effect stable thirty radioactive characterized atomic masses ranging stable decay product decay product trace highly unstable daughters half life hour natural decay product stable commonly referred half life seconds alpha radiation similarly derived stable named alpha half life seconds occur significantly decay series trace extremely unstable produced daughters belongs decay chain half life days products excluding marginal decay schemes short lived meaning corresponding indicative initial distribution decay goes following sequence days alpha decaying minutes alpha decaying minutes beta decaying minutes beta decaying alpha decaying longer half life years beta decaying days beta decaying days alpha decaying stable factor ratio activity short period responsible biological effects activity parent closed volume constantly supplied concentration short lived increase reached rate decay decay product equal factor activities equal meaning decay products stayed close parent long reached couple hours conditions additional increase exposure working level measure commonly mining detailed explanation given concentration units conditions met homes fraction typically daughters air takes longer decades come environment permits accumulation dust extended periods time decay products contribute overall radiation levels charge adhere surfaces dust particles attachment removes air usually causing factor atmosphere factor lowered air circulation air devices increased airborne dust particles including cigarette smoke high concentrations airborne contribute significantly human health risk factor found studies history etymology fifth radioactive element discovered friedrich reported experiments noticed compounds radioactive gas named marie observed gas emitted remained radioactive month later year robert university montreal noticed variations trying measure radiation noticed compounds continuously radioactive gas retains radioactive powers minutes called gas latin later demonstrated radioactive credited discovery element similar observed louis called names suggested gases eventually likeness gases observed chemical led sir william suggest contain new element noble gas family robert gray isolated determined density determined heaviest known gas wrote expression est fort expression awkward suggested new latin meaning shining emphasize property accepted international commission atomic weights international committee chemical elements international union pure applied chemistry chose names later numbered instead named element took stable renamed renamed late 1960s element referred simply synthesized compound obtained danger high exposure mines reaching found long known described disease miners recommended ventilation mines avoid mountain sickness condition identified lung cancer investigation miners germany major studies health occurred context mining region studies followed decades health effects miners southwestern united_states employed early cold war standards implemented presence indoor air documented early beginning 1970s research initiated address sources indoor concentration health effects approaches united_states problem indoor received widespread publicity intensified investigation widely publicized incident routine monitoring pennsylvania nuclear power plant worker found contaminated high contamination home subsequently identified responsible contamination occurrence concentration units discussions concentrations environment refer average rate production decay series environment short half life seconds versus days respectively concentration atmosphere usually measured cubic meter derived unit unit measurement common typical domestic average indoors varies widely outdoors mining industry exposure traditionally measured working level cumulative exposure working level month equals combination short lived daughters air releases potential alpha energy equivalent cubic meter air unit cumulative exposure expressed hours cubic meter equivalent exposure working month hours equals cumulative exposure cumulative exposure roughly equivalent living year atmosphere concentration levels measured rate deposition weather dependent concentrations found natural environments low detected chemical means relatively high concentration corresponds cubic meter average concentration atmosphere air air activity entire earth atmosphere originates tens grams consistently replaced decay larger amounts natural produced radioactive decay found rock rocks granite lesser degree common rocks limestone square mile surface soil depth inches km2 depth contains approximately releases small amounts atmosphere global scale estimated million released soil annually concentration varies widely place place open air ranges ocean caves mines ill houses concentration climbs concentration higher mining contexts ventilation regulations maintain concentration mines working level levels ranging nearly air measured concentration air healing gallery averages value appears decay chain series marginally series element naturally ground building materials world traces found particularly regions soils containing granite higher concentration regions prone high emissions rare gas usually freely faults fragmented soils accumulate caves water owing short half life days concentration decreases quickly distance production area increases concentration varies greatly season atmospheric conditions instance shown accumulate air meteorological little wind high concentrations found spring waters hot springs towns boulder montana bad germany country japan rich springs classified mineral water concentration activity mineral water reaches italy natural concentrations earth atmosphere low rich water contact atmosphere continually lose ground water higher concentration surface water continuously produced radioactive decay present rocks likewise saturated zone soil frequently higher content zone losses atmosphere apollo passed plateau moon detected significant rise alpha particles thought caused decay presence later data obtained lunar alpha particle found petroleum similar pressure temperature curve oil separate based boiling points carrying separated oil radioactive decaying products petroleum natural gas industry contain daughters scale oil rich water oil gas contains form solid form inside accumulation buildings high concentrations homes discovered chance stringent radiation testing conducted nuclear power plant entrance revealed stanley engineer entering plant contaminated radioactive substances typical domestic approximately indoors level found buildings enters building directly soil lowest level building contact ground high levels water supply increase indoor air levels typical entry points buildings cracks solid foundations construction joints cracks walls gaps suspended floors gaps service pipes inside walls water supply concentrations location differ factor period hour concentration room building significantly different concentration adjoining room distribution concentrations generally change room room readings averaged according regulatory indoor concentration usually assumed follow distribution given territory geometric mean generally estimating average concentration area mean concentration ranges european countries typical geometric standard found studies range meaning given rule concentration expected times mean concentration cases highest average concentrations united_states found iowa mountain areas southeastern pennsylvania highest readings recorded irish town county prompting local fears lung cancer iowa highest average concentrations united_states significant ground rocks canadian shield deposited soils making rich iowa farmland cities state iowa city passed requirements resistant construction new homes locations subsequently built resulting possible increased exposure gas way know present air water perform tests united_states test kits available public retail stores hardware stores home use testing available licensed professionals home efforts reduce indoor levels called environmental protection agency recommends houses tested industrial production obtained product processing transferring solutions gas mixture extracted solutions contains mixture passing copper remove remove moisture condensed liquid nitrogen gases regulated available small quantities measurement systems price solution contains actual given moment produced solution half life years alpha particle producing collects samples rate day quickly achieved produced steady flow activity equal half life days escapes capsule concentration scale applications medical century form treatment small sealed room patients exposed medicinal effects nature radiation apparent later damaging kill cells increase health healthy cells radiation causes formation free results genetic cell damage resulting increased rates illness including cancer exposure process known radiation suggested auto immune diseases result late 20th century early 21st century health mines established basin montana attracted people seeking relief health problems limited exposure radioactive water practice discouraged documented ill effects high radiation body radioactive water applied czech_republic discovery bad austria rich springs traditional japanese drinking therapy applied bad germany therapy carried austria poland romania boulder united_states europe people sit minutes hours high atmosphere belief low radiation produced commercially use radiation therapy replaced nuclear seeds gold glass primarily treat gold seeds produced filling long tube pumped source tube divided short sections cutting gold layer keeps filters alpha beta allowing gamma rays escape kill tissue activities range seed gamma rays produced short lived elements decay chain decay products short lived seed left place half lives days original level stage predominant activity originates decay product half life years times activity descendants early 20th century gold contaminated entered jewelry industry gold seeds held melted decayed scientific soil varies soil type surface content outdoor concentrations track air masses limited degree fact use atmospheric scientists rapid loss air comparatively rapid decay research studies interaction ground water streams significant concentration stream good indicator local ground water soil concentration experimental way map buried close geological faults concentrations generally higher faults similarly found limited use researchers investigated changes concentrations earthquake prediction half life approximately days means found shortly produced radioactive decay chain reason increases concentration generation new cracks underground allow increased ground water circulation generation new cracks assumed major earthquakes 1970s 1980s scientific measurements emissions near faults found earthquakes occurred signal detected earthquake follow dismissed unreliable indicator investigation possible precursor nasa known emitted power stations present material pumped deep underground rapidly hazard demonstrated investigations addition typical systems material deep underground releasing surface environmental impact minimal 1940s 50s industrial ray sources available world war quickly replaced application lower cost hazard alpha radiation health risks mines decay products classified international agency research cancer humans gas lung cancer particular concern people exposed elevated levels sustained periods 1940s 50s safety standards requiring expensive ventilation mines widely implemented exposure linked lung cancer non smoking miners hard rock materials czech_republic later miners southwestern united_states south_australia despite hazards known early 1950s hazard remained poorly managed mines 1970s period opened mines usa general public advertised alleged health benefits breathing gas underground health benefits claimed including pain relief proven false time ventilation measures reduce levels affected mines continue operate recent years average annual exposure miners fallen levels similar concentrations homes reduced risk induced cancer health issues persist currently employed affected mines employed past relative risk miners decreased ability detect excess risks population addition lung cancer researchers possible increased risk exposure support studies general population inconsistent study miners found exposure chronic miners ore transportation workers worked industry united_states 1940s eligible compensation radiation exposure compensation act surviving relatives apply cases employed person deceased domestic level exposure exposure daughters linked lung cancer numerous case control studies performed united_states europe china approximately deaths year induced lung comprehensive studies performed united_states william field colleagues found increased lung cancer risk protracted action level north american european analyses support findings models residential exposure based studies miners direct estimates risks posed desirable difficulties measuring risk relative smoking models effect use considered second leading cause lung cancer leading environmental cause cancer mortality united_states environmental protection agency reached similar conclusions united_kingdom france exposure homes offices arise certain rock formations certain building materials greatest risk exposure arises buildings foundation leaks allow air soil dwelling rooms action reference level presented recommended reference level national reference level dwellings recommendation says possible selected highest level national reference level limit represent maximum acceptable annual average concentration dwelling concentration home varies depending organization recommendation example united_states environmental protection agency encourages action taken concentrations low european_union recommends action taken concentrations reach old houses new ones july health protection agency issued new advice setting target level whilst retaining action level levels apply norway new measures taken accumulation relationship smoking results studies indicate risk lung cancer increases exposure residential known example source error smoking addition smoking important risk factor lung cancer west tobacco smoke estimated cause lung tendency hypothetical lung cancer risks risk smoking results studies interpreted caution according risk lung cancer significant effects smoking population people total die lung cancer compared people total people smoked excluded risk non primarily explained combination effect passive smoking like known suspected external risk factors lung cancer threat demonstrated european study commentary study stated appropriate talk simply risk homes risk smoking compounded effect smoking effect small insignificant according european study difference risk types small cell lung practically affects high risk types type primarily affects risk appears lower study radiation post shows simple models previously assess combined separate risks radiation smoking need developed supported new discussion calculation method routinely relationship passive smoking important question passive smoking cause similar effect residential studied basic data european study makes impossible exclude effect explanation limited increase risk stated non study included cases lung cancer control group showed exposure increased risk lung cancer group exposed passive smoking home appeared bear entire risk increase exposed passive smoking increased risk increasing level drinking water effects similarly unknown studies found biological half life ranges minutes percent removal minutes national research council investigated issue drinking water risks associated considered water underground sources contain significant amounts depending surrounding rock soil conditions surface sources generally drinking water released water temperature increased pressure decreased water conditions release exposure occur water concentration increase indoor airborne concentration normal conditions testing relatively simple tests gas countries tests areas known systematic hazards detection devices commercially available digital provide ongoing measurements giving daily weekly short term long term average digital display short term test devices initial screening purposes inexpensive cases free important taking short term tests strictly followed kit includes collector user hangs lowest floor house days user sends collector laboratory analysis long term kits taking collections year available open land test kit test emissions land construction begins concentrations vary daily accurate exposure estimates require long term average measurements spaces individual spends significant time levels naturally factors like weather conditions initial test accurate assessment home average level levels maximum day pressure greatest high result repeating test undertaking expensive projects measurements warrant long term test measurements warrant short term test measures delayed real estate advised delay decline purchase seller successfully half life days removing source greatly reduce hazard weeks method reducing levels modify building ventilation generally indoor concentrations increase ventilation rates decrease place concentration tends align outdoor values typically ranging principal ways reducing accumulating house sub slab soil increasing floor ventilation improving ventilation house avoiding transport basement living rooms installing system basement installing positive positive supply ventilation system according method reduce primarily vent pipe system fan pulls beneath house outside called sub slab active soil soil generally indoor sub slab exhausting laden air outdoors away windows building openings generally recommends methods prevent entry soil example prevents entering home drawing home pipe pipes air home quickly recommend use sealing reduce sealing shown lower levels significantly consistently positive pressure ventilation systems combined heat recover energy process exchanging air outside simply exhausting basement air outside necessarily viable solution actually draw gas dwelling homes built crawl space benefit collector installed barrier sheet plastic covers crawl space states effective method reduce levels homes involves covering earth floor high density plastic sheet vent pipe fan draw sheet vent outdoors form soil called properly applied effective way reduce levels homes


greek stone chemical element symbol atomic number soft silver white metal belonging metal group chemical elements standard conditions metal dense solid element like metals highly reason typically stored mineral oil cut open exhibits metallic contact moist air surface quickly dull gray black high occurs freely nature instead appears compounds usually occurs number minerals present ocean water commonly obtained commercial scale isolated mixture potassium nucleus instability stable found nature lowest binding energies stable relative nuclear instability common solar system chemical elements light atomic weight related reasons important links nuclear physics fully man nuclear reaction serves fusion fuel staged weapons compounds industrial applications including heat resistant glass iron steel aluminium production batteries batteries uses consume quarters production trace amounts present organisms element serves apparent vital biological function animals plants survive good health non vital functions ruled administered proved useful mood drug treatment disorder humans properties atomic physical like metals single electron easily given form good conductor heat electricity highly element metals low proximity electron nucleus remaining lower energy participate chemical bonds metal soft cut knife cut possesses white color quickly changes gray lowest melting points metals highest melting boiling points metals low density comparable pine wood dense elements room temperature solid element potassium furthermore apart hydrogen dense liquid element dense liquid nitrogen float metals float water potassium thermal expansion twice aluminium times iron standard pressure higher temperatures high pressures temperatures like undergoes phase change crystal system layer repeat higher temperatures transforms face centered cubic body centered cubic liquid temperatures structure prevalent multiple forms identified high pressures mass specific heat capacity kilogram highest metal heat transfer applications chemistry compounds water easily noticeably energy metals reaction forms hydrogen gas solution water usually stored petroleum heavier metals stored dense substances mineral oil dense fully submerged moist air rapidly form black coating result secondary reaction placed flame compounds striking crimson color burns strongly flame brilliant silver burn oxygen exposed water water potentially explosive exposed air especially water metals water reaction normal temperatures hydrogen produced metals fires difficult requiring dry powder fire class type metal nitrogen normal conditions diagonal relationship element similar atomic radius chemical metals include formation reaction formation burnt similar thermal instability metal hydrogen gas high temperatures produce known compounds include compounds known combines form aluminium commonly reducing agent organic synthesis multiple known direct bond carbon effectively creating extremely powerful bases compounds tend aggregate high symmetry clusters relatively common weakly interacting van der compound detected low temperatures gas experimental evidence suggests form temperatures exhibits fully confirmed example observed gas conditions reservations reality demonstration largely direct observation spins parallel naturally occurring composed stable abundant natural abundance natural low nuclear binding energy compared neighboring elements periodic table low numbered element produce net energy nuclear lower binding energies stable result light atomic weight common solar system chemical elements seven characterized stable half life half life remaining radioactive half lives shorter shortest lived half life elements properly produced big bang small produced stars thought burned fast produced additional small amounts generated solar wind cosmic rays hitting heavier early solar system radioactive decay created stars stellar burned generated carbon stars substantially wide variety natural processes including mineral formation chemical precipitation exchange substitute iron sites clay minerals preferred resulting light processes rock alteration exotic known exhibit nuclear halo process known laser separation separate particular nuclear weapons manufacture nuclear physics applications major source artificial light retained industry military extent caused slight change natural sources rivers led unusual uncertainty standardized atomic weight quantity depends natural abundance naturally occurring stable available commercial mineral sources occurrence astronomical according modern theory stable elements synthesized big bang generated big bang dependent number accepted values abundance calculated universe older stars younger stars lack older stars apparently caused mixing interior stars destroyed produced younger stars collision temperatures million degrees stars easily attain temperature interiors abundant current predict later generation stars elements synthesized big bang markedly abundant elements result low temperature necessary destroy lack common processes produce found brown dwarf objects certain orange stars present cooler massive brown destroyed red dwarf stars presence stars test differentiate smaller sun certain orange stars contain high concentration orange stars found higher usual concentration orbit massive objects stars black holes gravity evidently pulls heavier surface hydrogen star causing observed terrestrial widely distributed earth naturally occur form high total content large estimated billion tonnes element exists relatively constant concentration parts million higher concentrations approaching found near estimates earth content range weight keeping forms minor rocks largest concentrations provide greatest abundance containing minerals commercially viable sources significant mineral newer source clay active development western corporation united_states earth crust 25th abundant element according handbook natural calcium comparatively rare element found rocks low concentrations fairly large number mineral deposits comparatively actual potential commercial value small low grade geological survey estimates chile largest reserves far million tonnes highest annual production tonnes largest reserve bases area million tonnes major suppliers include australia argentina china june new_york_times reported american conducting ground surveys dry salt lakes western afghanistan believing large deposits located pentagon officials said initial analysis location province showed potential deposits large world largest known reserves estimates based principally old data gathered mainly soviets occupation afghanistan stephen head afghanistan minerals project said unaware involvement new surveying minerals afghanistan past years aware discoveries said biological found trace numerous plants invertebrates concentrations parts billion concentration slightly lower nearly tissue body contain ranging marine organisms tend terrestrial organisms role organisms unknown history discovered brazilian chemist statesman island sweden august working laboratory chemist detected presence new element analyzing ore element formed compounds similar potassium water gave material greek word meaning stone reflect discovery solid mineral opposed potassium discovered plant ashes known partly high abundance animal blood named metal inside material later showed element present minerals christian observe bright red color flame tried failed pure element isolated william thomas obtained process previously employed chemist sir metals potassium described pure estimating contained metal estimated atomic weight modern value larger quantities produced robert discovery procedure led commercial production german company performed liquid mixture potassium production use underwent drastic changes history major application high temperature aircraft engines similar applications world war shortly use supported fact based higher melting point calcium based small market supported small mining operations united_states demand increased dramatically cold war production nuclear fusion weapons produce useful production form solid fusion fuel inside hydrogen bombs form united_states prime producer period late 1950s mid-1980s end roughly tonnes depleted affect measured atomic weight standardized chemicals atomic weight natural sources contaminated discharged separation facilities found way ground water decrease melting temperature glass improve melting behavior aluminium hall process uses dominated market middle 1990s end nuclear arms race demand decreased sale department energy open market reduced prices mid-1990s companies started extract proved expensive method underground open pit mining mines closed shifted focus materials ore mined competitive price example mines near kings mountain north_carolina closed turn 21st century development batteries increased demand dominant use surge demand batteries 2000s new companies expanded extraction efforts meet rising demand production production greatly increased end world war metal separated elements minerals extracted water mineral springs pools deposits metal produced mixture fused potassium usd usd reserves worldwide identified reserves estimated geological survey million tonnes difficult accurately estimate world reserves deposits found south_america mountain chain chile leading producer followed argentina countries recover pools united_states recovered pools nevada half world known reserves located central eastern slope negotiated japanese french korean firms begin extraction according desert million tonnes newly discovered deposit wyoming rock springs estimated tons additional deposits formation million tons opinions differ potential growth study concluded production sufficient small fraction future global market requirements demand portable electronics sector absorb planned production increases decade mass production environmentally sound cause ecological damage ecosystems protected propulsion incompatible notion green car according study conducted lawrence berkeley national laboratory university california berkeley currently estimated reserve base limiting factor large scale battery production electric vehicles estimated billion based batteries built current reserves car study researchers university_of_michigan ford motor company found sufficient resources support global demand including required potential widespread transportation use study estimated global reserves million tons total demand year period analyzed million tons depending scenarios economic growth recycling rates june stated demand growing percent year according credit rate exceeds projected availability percent publication compared situation oil higher oil prices spurred investment expensive oil sands production techniques price continue rise expensive production methods boost total output receive attention investors financial crisis major suppliers dropped prices rose business week article outlined space controlled second largest followed backed henry philadelphia based global consumption jump metric tons year tons match demand batteries growing percent year percent percent overall gain wells potential source wells carry surface recovery demonstrated field separated simple process environmental costs primarily operating net environmental impacts positive present practical extraction techniques extraction world production south_america containing extracted underground pools concentrated solar materials received million grant department energy pilot project financial feasibility high quality uses power plant california imperial valley extracted fluid passed series membranes filters materials extract standard extraction technique water batch takes months researchers announced new extraction process cell uses membrane pass membrane reverse reverse proposed alternative uses glass widely processing reducing melting point material leading improved physical properties including low thermal expansion worldwide single largest use compounds containing generally application converts heating electrical electronics late 20th century important component battery high potential low atomic mass high power weight ratio typical battery generate approximately volts cell compared volts lead acid volts carbon cells batteries high energy density confused batteries primary batteries compounds batteries use include battery iron battery battery common use strong base heated fat produces soap soap ability manufacture purpose high temperature continuous casting mould increases use accounts global use compounds sand iron casting reduce aluminium hall process reducing melting temperature increasing electrical resistance use accounts production metallic promotes metals process forming absorbing metal aluminium copper high performance aircraft parts aluminium found effective assisting perfection electronic components electric batteries devices chemical industrial uses compounds red fireworks air gas streams confined areas aboard spacecraft submarines carbon dioxide removal air carbon dioxide air forming preferred low weight presence moisture carbon dioxide form releases oxygen reaction follows aforementioned compounds oxygen candles supply submarines oxygen include small amounts aluminum iron artificially grown crystal clear transparent specialist vacuum applications lowest transmission range deep common materials finely divided powder radiation sample exposed radiation crystal defects heated resolve release bluish light intensity proportional absorbed dose allowing focal lenses high non makes useful non linear applications extensively products mobile phones optical components crystals applications mobile phones organic chemistry compounds widely production fine chemicals industry dominant consumer compounds production fine chemicals compounds function strong bases formation carbon carbon bonds compounds prepared metal compounds prepare organic compounds popular compounds include aluminium commonly extremely strong bases called military applications metallic complex high energy rocket aluminum solid fuel mark torpedo stored chemical energy propulsion system uses small tank gas sprayed block solid reaction generates heat creating steam propel torpedo closed cycle containing weapons core bomb nuclear valued source material production nuclear fusion natural contains large amounts produced separation use nuclear weapons gained interest use nuclear fusion fuel choice early versions hydrogen bomb bombarded produce reaction fully understood hydrogen bombs tested responsible runaway yield castle nuclear test fusion reaction relatively easy achieve details remain secret apparently plays role modern nuclear weapons fusion material highly enriched forms basic constituent salt mixture liquid nuclear exceptionally stable low melting points addition low thermal capture cross sections poison reactions inside nuclear hypothetical nuclear fusion power plants produce confined fuel naturally occurring extremely rare produced surrounding reacting blanket containing reaction produce source alpha particles bombarded accelerated formed undergoes form alpha particles feat called splitting time fully man nuclear reaction produced government office said shortage critical operation american nuclear places ability continue provide electricity risk problem stems decline nuclear infrastructure equipment needed separate cold war shut machinery huge surplus separated consumed twentieth century report said years million million ability separate use heat water high pressure transfer heat heat prone use counteract effects acid added water absorb excess medicine useful treatment disorder helpful related disorder major depression active increase risk developing cardiac born women pregnancy researched possible treatment cluster precautions requires special handling avoid skin contact breathing dust compounds initially nose throat higher exposure cause buildup fluid lungs leading metal handling hazard contact moisture produces safely stored non compounds regulation jurisdictions limit sale batteries readily available source ordinary consumers reduce birch reduction method employs solutions metals dissolved carriage shipment kinds batteries prohibited aboard certain types transportation particularly aircraft ability types batteries fully discharge rapidly short leading possible explosion process called thermal runaway consumer batteries built thermal protection prevent type incident designed limit short circuit currents internal shorts manufacturing defect physical damage lead spontaneous thermal runaway


chemical element symbol atomic number soft gray post transition metal found free nature isolated resembles tin exposed air william discovered independently acid production newly developed method flame produces notable green line greek meaning green shoot named isolated precipitation melting resultant powder exhibited powder precipitated international exhibition opened year tends states state resembles elements group aluminum state far prominent elements recalls chemistry metals found potassium based handled ways like potassium pumps living cells commercially produced potassium heavy metal approximately production electronics industry remainder industry glass manufacturing infrared small amounts agent nuclear medicine scan type nuclear cardiac stress test nearly highly toxic quantity historically rat use compounds restricted banned countries notably poisoning results hair loss historic popularity murder weapon gained notoriety poison inheritance powder alongside characteristics arranged electron configuration sixth shell pair effect electron pair difficult involved chemical bonding heavier elements available metallic bonding similar neighboring elements mercury lead like soft highly electrically conducting metal low melting point number standard depending reaction study reported reflecting greatly decreased stability state element group reduction state state spontaneous bond energies decrease group energy released forming additional bonds attaining state energy needed involve accordingly basic iii acidic showing general rule elements lower states cut knife room temperature metallic exposed air quickly bluish gray resembling lead preserved oil heavy layer builds left air presence water formed acid dissolve rapidly acid forms layer atomic masses range stable nearly natural stable half life years activation stable nuclear useful half life hours electron capture rays total abundance good imaging characteristics excessive patient radiation dose popular nuclear cardiac stress tests compounds iii iii compounds resemble corresponding aluminium iii compounds moderately strong agents usually unstable illustrated positive reduction potential couple mixed compounds known contain iii iii black solid forming oxygen simplest possible compound unstable exist bulk instability state poor overlap hydrogen stable distinct lighter group elements stable group instance iii structure lighter group form complex solution room temperature contains linear actually compound iii exist stable keeping large size structure distorted structures like analogous silver compounds stability compounds demonstrates differences rest group stable known compounds compounds tend unstable trend decreasing thermal stability group chemical bond lowest group especially compounds type forms stable solution like linear like corresponding compounds low melting points like compounds contain contrast iii history greek meaning green shoot discovered flame comes bright green lines publication improved method flame robert discovery years flame approved method determine composition minerals chemical products william started use new method william compounds deposited lead chamber acid production plant near mountains obtained samples research august years earlier able small quantities new element determine properties compounds similar determine composition containing substance deposited production acid noticed new green line concluded new element present received material acid plant friend product available large quantities started new element source fact able work ample quantities enabled determine properties compounds addition prepared small metallic prepared obtained scientists discovered independently large work especially isolation metallic tried secure priority work awarded medal international exhibition london discovery new abundant source heavy protest received medal discovery new element controversy scientists continued discussion ended elected fellow royal society june dominant use use poison accidents use poison banned united_states presidential executive order february subsequent years countries banned use occurrence production abundant element earth crust concentration estimated association potassium based minerals soils generally economically sources major source practical purposes trace found copper lead heavy metal found minerals occurs trace element iron extracted product mineral production acid obtained lead found ocean floor contain collection continues expensive potential damaging environment oceans addition minerals containing occur nature complexes primarily contain copper lead silver minerals rare commercial importance sources deposit southern macedonia area actively mined deposit contains loosely estimated tonnes source rare minerals example united_states geological survey estimates annual worldwide production metric tonnes product copper lead extracted collected end process raw materials production contain large amounts materials step use base acid material times precipitated solution remove end converted extracted platinum steel plates production decreased period metric tonnes tonnes small deposits relatively high content possible increase production new application hypothetical containing high temperature practical widespread use outside laboratory applications historic uses widely rat poison killer use prohibited united_states safety concerns countries followed example following years treatment skin reduce night tuberculosis patients use limited narrow index development advanced conditions crystals infrared optical materials harder common infrared transmission significantly longer trade refers material manufacture glasses high index combined production high density glasses low melting points range glasses room temperature properties similar ordinary glasses water unique electronics electrical changes exposure infrared light making compound useful infrared detection improves performance trace amounts application crystals gamma radiation detection devices crystals small improve efficiency generators dissolved oxygen contain high temperature research activity ongoing develop high temperature materials applications magnetic resonance imaging storage magnetic energy magnetic propulsion electric power generation transmission research applications started discovery calcium copper discovered transition temperatures mercury transition temperatures ambient pressure nearly high world record holding mercury medical widespread application nuclear medicine radioactive half life hours main substance nuclear stress tests risk patients disease generated generator similar generator generator contains half life hours electron capture produced bombardment reactions stress test stress test form tissues tissue blood supply viable cardiac cells normal exchange pumps pumps transported cells exercise widening normal produces steal areas areas tissue remain cold post stress indicate areas benefit indicates existence steal presence disease uses mercury forms reported freeze freezing point mercury low temperature switches organic synthesis iii useful performing different constituent plates batteries added gold plating increase speed plating reduce grain size gold layer saturated solution equal parts water known solution mobile liquid color changes yellowish clear reducing concentration density solution heaviest solutions known 20th century measuring density minerals method use discontinued high solution metal lamps metals allows lamp temperature color rendering shift output green region useful underwater lighting compounds extremely toxic handled great care numerous recorded cases fatal poisoning people exposed workplace breathing skin absorption eye contact safety health administration set legal limit exposure limit exposure workplace skin exposure hour national institute safety health set recommended exposure limit skin exposure hour levels immediately dangerous life health contact skin dangerous adequate ventilation provided melting metal compounds high readily absorbed skin exposure exceed cubic metre hour time weighted average hour work week readily absorb skin care taken avoid route exposure absorption exceed absorbed dose received suspected human long time compounds readily available rat poison fact water nearly led frequent caused accident criminal intent main methods removing radioactive normal humans use prussian blue material day prussian blue fed mouth person passes digestive system comes remove blood later stage treatment additional potassium tissue according united_states environmental protection agency man sources pollution include cement factories coal burning power plants metal main source elevated concentrations water ore processing operations


chemical element symbol atomic number dense gray metal readily oxygen water forms chemical compounds usually present state assume states average concentrations earth crust typically order parts reach parts million ore deposits high high currently uses outside scientific research purpose extracted spent nuclear fuel identified named short half life specific studied stable discovered chose named finally confirmed new meant parent reflected fact product radioactive decay noted john arnold working frederick credited discovering stable delayed announcement called service world war longest lived abundant nearly naturally occurring half life years decay product smaller trace amounts short lived nuclear occur decay chain results decay chain events produce intermediate product based nuclear removed active zone breeding process analysis relative concentrations water minerals dating sediments years old modeling geological processes history predicted existence element element group unknown time positioned leaving space 1950s periodic tables published structure long time searched element similar chemical properties making discovery nearly impossible heavier later found element william isolated intensely radioactive material characterize new chemical element named dissolved phase contains method 1950s compounds identified encountered studies decay chains named new element latin word meaning brief short short half life hours groups scientists germany frederick john great_britain independently discovered having longer half life years changed new element decay chain greek meaning ease pronunciation shortened discovery completed gaps early versions periodic table proposed brought fame involved scientists von produced isolated different procedures vacuum method called van boer process converted reduced vacuum electrically heated metallic united_kingdom atomic energy authority produced grams pure processing tonnes waste material stage process cost usd years world significant supply provided laboratories scientific studies oak ridge national laboratory provided cost usd discovered stable half life years half life days half life days remaining half lives shorter days majority half lives seconds nuclear half life half life minutes primary decay mode lighter including stable alpha decay primary mode heavier beta decay primary decay products lighter including primary decay products heavier occurrence expensive naturally occurring elements found form occurring different energy states nearly natural alpha formed decay beta produced result decay nearly occurs concentrations parts million parts ore usual content closer czech_republic democratic republic dispersed natural materials water lower concentrations order corresponds times sandy soil particles water water present sample soil higher measured soils nuclear major produced nuclear undesirable usually removed adding complexity design operation particular reactions produces quickly half life hours waste long half life years major contributor long term spent nuclear fuel formed capture captures converts non relatively long half life days high cross section capture called poison instead rapidly decaying useful significant fraction converts non efficiency avoid extracted active zone salt operation achieved meters tall columns dissolved simplified scenario reduces metal extracted salt cycle merely carrier chosen low melting point low pressure good preparation advent nuclear separated scientific experiments produced intermediate product nuclear high temperature formula times half lives metal prepared reduction calcium temperature physical chemical properties positioned periodic table left right physical properties intermediate dense rigid lighter melting point lower higher thermal expansion electrical thermal elements comparable typical post transition metals estimated shear similar metal gray preserved time air easily oxygen water room temperature body centered structure regarded distorted body centered cubic structure change compression structure changes face centered cubic cooling high temperature thermal expansion phase room temperature magnetic transitions known temperature temperatures room temperature turns cooling exists major states solutions states observed solid phases electron configuration neutral state corresponds low energy favored configuration states easily form water predominant known include chemical compounds space group number number formula units unit cell stands face centered cubic symmetry density measured directly calculated parameters oxygen containing known metal states stable white produced air temperature crystal structure cubic chemical composition non described phase symmetry reported black dioxide obtained reducing hydrogen readily concentrated easily acid dioxide converted heating oxygen containing atmosphere observed thin coating metal isolated bulk form forms mixed metals metals crystals chemical formula structure distorted rock salt structure oxygen close packed materials coordinated combines rare earth metal form mixed structure basic easily convert form etc usually white brown heating air converts white produced reacting acid gas atmosphere heating product reaction products acid heating higher temperatures atmosphere analogous groups form symmetry heating air forms white crystals arranged coordinated coordination color yellow coordination changes brown unknown coordination arrangement square brown colored iii reported coordinated arrangement structure symmetry chain lie like plane form coordination originates bonds belonging nearby chains compounds easily water lower temperatures prepared reacting obtained mixture hydrogen hydrogen large excess hydrogen required remove atmospheric oxygen leaks reaction prepared reacting carbon temperature products removed reduction hydrogen yields yellow green solid vacuum obtained directly dioxide treating carbon produced action aluminium hydrogen carbon mixture hydrogen alternative reaction hydrogen similar forms obtained slightly lower temperature result aluminium heated iii obtained heating vacuum forms mixed metals remarkable surrounded form nearly perfect cube complex known types white formula represented combination compounds obtained acid solution containing complexes small like crystal structure larger similar variation observed crystal symmetry dependent differed compounds known structure composed double chain units coordination arranged chains oxygen oxygen related light yellow non volatile solid cubic crystal obtained reacting mixture hydrogen carbon low state obtained direct action hydrogen metal product bright yellow solid stable heating vacuum formed reduction carbon temperature forms include unusual structure chains coordination number surrounded compounds forms complex rings synthesized reacting ring substituted complex golden yellow analogous structure metal similar prepared reacting applications located periodic table numerous applications owing high high currently uses outside scientific research arises decay formed nuclear reaction subsequent beta decay thought able support nuclear chain reaction principle build nuclear weapons physicist walter estimated associated critical mass possibility ruled advent highly sensitive mass application geology possible ratio dating sediments years old modeling formation minerals particular evaluation oceanic sediments allowed reconstruct movements north_atlantic water bodies melting ice age glaciers related dating variations rely analysis relative concentrations long living members decay chain example elements outer shell favor states respectively different physical chemical properties compounds poorly solutions sediments precipitation rate faster concentration analysis half life years half life years allows improve accuracy compared measured double method weakly sensitive spatial distribution variations precipitation rate precautions toxic highly radioactive performed sealed glove box major specific activity primarily alpha particles energy stopped thin layer material slowly half life years specific activity alpha beta radiation shorter half life years turn lighter shorter half lives greater specific activities summarized table showing decay chain present small amounts natural products materials food water air absorbed blood remainder blood deposits bones goes liver rest leaves body biological half life years bones organs fast slow component liver half life days remain days corresponding values days days organs promotes cancer maximum safe dose human body corresponds times toxic acid maximum allowed concentrations air germany


radioactive chemical element symbol atomic number member element series named city berkeley california location university california radiation laboratory discovered december fifth element discovered major synthesized minute quantities dedicated high nuclear mainly oak ridge national laboratory tennessee usa research institute atomic russia production second important involves rare high energy alpha particles produced united_states practical application outside scientific research directed synthesis heavier elements batch prepared day period days oak ridge sample element time joint institute nuclear research russia bombarded days culmination russia collaboration synthesis elements soft white radioactive metal low energy relatively safe handle half life days strong alpha particles gradual transformation important consideration studying properties chemical compounds formation brings chemical contamination free radical effects self heating emitted characteristics physical soft white radioactive metal periodic table located right left shares similarities physical chemical properties density lies melting point higher relatively soft lowest bulk iii shows sharp peaks red light deep red near infrared internal transitions electron shell relative intensity peaks depends power temperature sample observed example glass melting glass presence room temperature material effective magnetic moment temperature magnetic moment equal theoretical value calculated simple atomic model cooling undergoes transition state dissolution acid standard conditions standard change formation obtained standard potential potential neutral ambient conditions assumes stable form symmetry space group parameters crystal double close packing structure layer sequence having similar structure forms crystal structure changes pressure temperature compressed room temperature transforms beta modification face centered cubic symmetry space group transition occurs change volume increases compression transforms structure similar transition accompanied volume decrease electron shell phase transitions observed heating transforms phase slightly different space group constant structure equivalent closest packing sequence abc phase gradually revert original phase room temperature temperature phase transition believed close melting point chemical like hydrogen converting iii state state stable especially solutions possibly compounds known existence uncertain reported mixed similar behavior observed solutions green color yellow acid orange yellow acid react rapidly oxygen room temperature possibly formation protective layer surface metals hydrogen form compounds nuclear excited states characterized mass numbers ranging radioactive longest half lives observed years years days half lives range days easiest soft particles detection alpha radiation weak respect radiation detect second important alpha occurrence half life far short present earth formation decayed earth concentrated certain areas atmospheric nuclear weapons tests sites nuclear incidents disaster mile island accident air base crash analysis debris testing site hydrogen bomb ivy mike november revealed high concentrations including reasons military secrecy result published nuclear produce storage fuel disposal beta half life years relatively long compared produced undesirable disposal products elements including occurred naturally natural nuclear longer history small amounts possibly produced previous nuclear experiments intentionally synthesized isolated identified december albert stanley thompson inch university california berkeley similar nearly simultaneous discovery element element new elements element produced choice element followed previous tradition group draw analogy newly discovered element positioned periodic table previously named continent honored scientists marie named explorer rare earth elements discovery report berkeley group reads suggested element given symbol city berkeley manner similar naming chemical atomic number derived town sweden rare earth minerals found tradition ended naming discovered related discovery place difficult steps synthesis separation final products production sufficient quantities target material solution coated platinum foil solution converted dioxide target alpha particles hours inch lawrence radiation laboratory university california berkeley reaction induced yielded free formula coating dissolved acid precipitated concentrated solution product dissolved acid separate solution added mixture heated convert dissolved state precipitated addition acid iii step yielded mixture accompanying product expected element form mixture converted corresponding treating potassium dissolved acid separation carried presence acid solution weakly acidic medium exchange elevated temperature separation behavior unknown element anticipated analogy curves results disappointing alpha particle signature detected product search characteristic rays conversion electron signals resulted identification mass number uncertain initial report later established synthesis extraction preparation produced bombarding lighter nuclear common case fuel produced capture called reaction fusion followed beta decay formula times half lives source high times higher conventional nuclear high oak ridge national laboratory tennessee usa higher promotes fusion reactions involving converting formula short half life minutes conversion low probability instead transforms beta decay formula produced long half life days capture product relatively short half life hours yield heavier instead formula stable production nuclear inefficient long half life potential allow sufficient time beta decay capturing accessible available small quantities grams produced period high price order usd obtained bombarding mixture particles direct detection hindered strong signal interference existence new proven growth decay product previously characterized half life estimated hours reliable value known produced year alpha particles formula synthesized bombarding converts electron capture half life minutes search initially suspected unsuccessful synthesized formula separation fact readily assumes state relatively stable state greatly assists separation away inevitably produced relatively large amounts nuclear synthesis favor state fact known initial experiments complex separation procedure agents applied iii solutions convert state silver lead procedures extracted exchange extraction liquid liquid extraction procedures separate absent target created nuclear decay chains detailed procedure adopted oak ridge national laboratory follows initial mixture processed exchange reagent precipitated filtered dissolved acid treated high pressure exchange phase extracted procedures described reduction obtained state yields solution nearly free contains separated round exchange treatment bulk metal preparation order characterize chemical physical properties solid compounds program initiated material testing idaho resulted preparation target production quantities stanley thompson continuous target years method way producing amounts element solid state studies conducted sized samples world major sources high oak ridge national laboratory tennessee usa loop research institute atomic russia dedicated production elements atomic number greater facilities similar power levels expected comparable production capacities elements quantities produced publicly reported typical processing campaign oak ridge tens grams produce quantities quantities quantities total produced oak ridge metal sample weighing prepared reduction iii suspended wire containing later metal samples weighing obtained method formula similar results obtained metal produced reduction compounds known state brown solid iii yellow green solid melting point formed reduction molecular hydrogen formula heating undergoes phase change undergoes phase change phase behavior typical reported gray solid exact chemical composition remains uncertain assumes states state stable especially solutions known solid phase coordination coordination number coordination coordination yellow green solid iii yellow green solid structures stable phase low temperatures iii heating transforms structure found iii visible amounts iii isolated characterized weighed prepared introducing hydrogen evacuated tube containing temperature green solid melting point iii heating nearly melting point converts phase forms iii known having coordination coordination stable transforms phase heating important phenomenon radioactive studied crystal forms structure fresh aged samples ray period longer years beta decayed change structure observed transformation differences noted example reduced hydrogen result reproduced individual samples samples containing occurs rate day obstacle studying properties chemical contamination alpha brings undesirable self damage crystal resulting self heating chemical effect avoided performing measurements function time obtained results compounds type known elements nitrogen rock salt structure prepared reaction iii metallic elements elevated temperature high vacuum iii prepared treating mixture hydrogen carbon directly reacting metallic procedures yield brownish black crystals iii stable solutions iii prepared solid shows strong green light produced reacting metal hydrogen gas temperatures non nominal formula known including thermal atmosphere avoid yields crystals iii compound stable atmosphere compounds forms complex rings synthesized reacting iii amber color density complex stable heating melting high gradually destroys compound period weeks ring substituted yield optical absorption compound similar applications currently use outside basic scientific research common target prepare heavier elements useful source studies chemistry preference radioactive produced bombardment facilities batch prepared day days oak ridge target yielded joint institute nuclear research russia bombarding calcium days synthesis culmination russia collaboration lawrence national laboratory synthesis elements initiated nuclear fuel cycle nuclear properties different neighboring suggest perform poorly fuel nuclear specifically moderately large capture cross section thermal resonance integral low cross section thermal thermal converted quickly principle sustain nuclear chain reaction fast critical mass relatively high reduced water steel exceed world production maintain chain reaction thermal fast production complex availability lower critical mass bare sphere water steel thickness health issues little known effects human body elements drawn different radiation products alpha particles low energy emitted detection signal interference decay processes makes relatively harmless humans compared transforms half life days strong alpha dangerous handled glove box dedicated laboratory available data originate research animals rats ends blood stream goes bones remains years lungs biological half life years stays indefinitely balance organs promote cancer skeletal system radiation damage red blood cells maximum human skeleton


chemical element symbol atomic number fifth element group soft metallic earth metal high chemical found nature free element known pre modern history substance occur mineral prepared heating common naturally occurring minerals water originates derivative comes greek meaning heavy form identified new element reduced metal advent industrial applications metal historically vacuum tubes component high temperature added steel cast iron reduce size carbon grains metal compounds added fireworks green color heavy oil drilling fluid form ray agents imaging human tract compounds poisonous release characteristics physical properties soft white metal slight golden shade white color metal rapidly air yielding dark gray layer medium specific weight good electrical hard prepare properties accurately measured room temperature pressure body centered cubic structure distance expanding heating rate approximately soft metal melting temperature intermediate lighter heavier boiling point exceeds density intermediate chemical similar calcium exhibits state reactions highly release energy reaction oxygen air occurs room temperature stored oil gas atmosphere reactions carbon nitrogen hydrogen generally proceed heating reactions water release hydrogen gas hydrogen additionally form complexes metal readily attacked acid notable exception stops reaction forming combines metals including aluminium lead tin forming phases compounds typically white solid dissolved provide specific coloring calcium table given comparison known produced heating unlike calcium little solutions atmospheric fluctuations property equipment volatile compounds burn green pale green flame efficient test detect compound color results lines compounds growing class compounds example known occurs naturally earth mixture seven undergoes slow radioactive decay double beta plus decay expected decay similarly corresponding half lives exceed age universe thousand times relative natural weak pose danger life stable makes lighter abundant total known ranging mass stable half life approximately years half lives longer day states stable having half life hours history early middle ages knew minerals smooth like stones mineral found italy known stones attracted exposure light glow years properties heated described identified containing new element isolated years later similar studies called changed 18th century english william noted heavy mineral lead mines cumberland known isolated sir england analogy calcium named ending signifying metallic element robert obtained pure mixture production pure oxygen process large scale application 1880s replaced air early 1900s process air form releasing oxygen applied agent ray imaging digestive system occurrence production abundance earth crust sea water main commercial source called heavy mineral deposits spread world commercial source far important mineral main deposits located england romania ussr reserves estimated billion tonnes maximum production achieved million tonnes compounds production risen second half 1990s million tonnes china accounts output followed india morocco turkey iran mined ore washed crushed classified separated deep ore iron lead content high methods applied product pure mass purity minimal content iron dioxide reduced carbon water starting point compounds dissolved reaction oxygen gives acid carbon dioxide yield metal produced reduction aluminium compound produced intermediate metal note reduced remaining formed aluminium overall reaction produced collected cooler apparatus packed atmosphere method commercially yield commonly sold pure main calcium contributing similar reaction yields readily isolated method containing mineral occurs rare blue official state gem california applications metal metal aluminium remove unwanted gases vacuum tubes picture tubes suitable purpose low pressure oxygen nitrogen carbon dioxide water partly remove noble gases crystal application gradually disappearing rising popularity sets uses minor include aluminium structure bearing lead tin increase resistance spark steel cast iron calcium aluminium high grade steel mineral important petroleum industry example drilling fluid oil gas wells compound called french expression meaning permanent white filler ringing ink paper coating pigment form improve physical properties low relatively high density rays reason agent ray imaging digestive system meals pigment contains permanent white good covering power exposed compounds aside compounds find niche applications applications limited rat poison problem coating lamps release heavy element increases index glass compound reduce leaks rays ray tubes sets typically added fireworks green color species responsible brilliant green absence yellow apple green produced instead catalyst start reaction rail tracks green ammunition agent promising infrared applications wide transparency range high temperature cooled liquid nitrogen transition temperature exceeded boiling point nitrogen type compound composed iron combined electrically temporarily permanently biological dangers precautions high metal data available compounds water compounds poisonous low act muscle higher affect nervous system causing cardiac irregularities weakness anxiety ability block potassium channels critical proper function nervous system target organs water compounds eyes immune system heart respiratory system skin affect body strongly causing example dust containing compounds accumulate lungs causing condition called comparison classified dangerous good avoid potentially vigorous chemical reaction metal kept mineral contact air dangerous cause moisture friction heat sparks flames static electricity reactions avoided contact grounded work metal wear pre cleaned non sparking shoes flame resistant rubber clothes rubber gloves apron gas mask allowed smoke working area wash handling


chemical element symbol atomic number taken mineral important source word comes persian word meaning gold colored grey white strong transition metal resembles lesser extent mainly small amounts agent strong resistance forms variety compounds dioxide respectively occur naturally stable compounds known biological role characteristics white soft metal solid room temperature hard lesser powder form highly solid form prone highly resistant salt water agents dissolve acid especially present magnetic melting point boiling point scale elements block fourth lowest room temperature exhibits close packed crystal structure changes body centered cubic crystal structure exists phase melting point naturally occurring composed stable predicted undergo double beta decay observed half life years half life years longest lived natural common making common comprising artificial synthesized ranging atomic mass longest lived artificial half life years heaviest radioactive estimated half life radioactive mass number decay decay exception exist shortest half life longest lived half life minutes occurrence concentration earth crust sea water found nature native metal reflecting instability respect water principal commercial source mineral found primarily australia brazil india russia south_africa united_states smaller deposits world thirds mining occurs australia south_africa resources exceed million tonnes worldwide annual worldwide production approximately tonnes occurs minerals including commercially useful relatively abundant type stars detected sun lunar rock samples brought apollo missions moon high content relative terrestrial rocks production product mining processing minerals tin mining prices mineral steadily increased price metal decreased ton metal higher priced reduction processes expensive collected coastal waters bearing sand spiral remove lighter materials returned water natural components beach sand magnetic separation removed directly commercial applications small percentage converted metal metal produced reduction metal process commercial quality uses content important nuclear applications resulting metal sufficiently separation commercial metal typically contains problematic chemical properties similar absorbing properties differ strongly necessitating separation nuclear separation schemes use liquid liquid extraction derivatives exploits fact derivative slightly water method mainly united_states separated potassium water analogous derivative called primarily europe product quadruple vacuum arc melting process combined hot different rolling applications cured high pressure high temperature gas produces grade times expensive contaminated commercial grade removed nuclear applications absorption cross section times greater separated control rods compounds like transition metals forms wide range compounds coordination complexes general compounds state far fewer iii compounds known rare common dioxide known solid exceptional fracture chemical resistance especially cubic form properties useful thermal barrier coating common diamond substitute known type stars recognised detection lines visual spectrum unusual property dimensions heated substances expand heated rare water complex relatively complicated formula drilling tools cutting edges phases known common known structures far volatile corresponding tend called corresponding known unlike dissolve metal finishing industry agent promote paint organic derivatives chemistry study compounds containing carbon bond compound reported birmingham reagent prepared organic synthesis component produce application exploits ability form bonds carbon complexes derivatives example history containing mineral related minerals mentioned biblical writings mineral known contain new element analyzed island ceylon sri_lanka named new element attempted new element failed metal obtained form heating mixture potassium potassium iron tube crystal bar process known process discovered van jan boer industrial process commercial production metallic involves formation subsequent thermal superseded cheaper process developed william reduced applications approximately tonnes mined compounds directly high temperature applications material hard resistant chemical attack properties finds applications highly publicized main use white appearance materials chemical resistance aggressive environments metals dioxide laboratory material strong flexible knives blades cubic cut use jewelry component grinding wheels metal small fraction converted metal finds niche applications excellent resistance agent materials exposed aggressive environments surgical light watch cases high oxygen high temperatures exploited specialised applications explosive vacuum tubes property probably purpose including particles material explosive weapons combined effects bomb nuclear applications nuclear supply mainly form desired properties low capture cross section resistance normal service conditions efficient methods removing developed serve purpose disadvantage water high temperatures producing hydrogen gas accelerated degradation fuel rod reaction slow temperature reaction rapid metals undergo similar reactions reaction relevant instability fuel assemblies high temperatures reaction responsible small hydrogen explosion observed inside building mile island nuclear power plant time building damaged reaction occurred nuclear power plant japan cooling interrupted earthquake disaster march leading nuclear accidents hydrogen maintenance hall mixture hydrogen atmospheric oxygen exploded severely damaging installations buildings avoid explosion direct hydrogen open atmosphere preferred design option prevent risk explosion water buildings catalyst based installed converts hydrogen oxygen water room temperature hazard arises space industries materials fabricated metal space vehicles resistance heat needed high temperature parts blades jet engines stationary gas turbines increasingly protected thin layers usually composed mixture cameras applied tracking molecular pet cameras method called pet pet reached maturity technical development entering phase wide scale clinical applications recently complicated procedure requiring multiple steps improved procedure developed derivative better way binding reported new method fast consists steps uses widely available ingredients appropriate applications bearing compounds applications including dental knee hip replacements middle ear chain reconstruction prosthetic devices property utilized extensively benefit patients chronic kidney disease example primary component column dependent regeneration system known system introduced treatments performed column system system superseded 1990s expensive alternatives new based systems evaluated approved food drug administration solutions developed technology portable low water system developmental versions artificial kidney incorporated based technologies investigation oral therapy treatment highly selective oral designed specifically trap potassium preference tract defunct applications treat poison ivy discontinued occasionally caused skin reactions safety known biological role human body contains average daily intake approximately food water depending habits widely distributed nature found biological systems example wheat brown rice eggs ground beef commonly commercial products sticks water control pollution contaminated water short term exposure powder cause contact eyes requires medical attention persistent exposure results increased mortality rats guinea pigs decrease blood red blood cells dogs study rats given standard diet containing adverse effects growth rate blood parameters mortality safety health administration legal limit exposure limit exposure hour national institute safety health recommended exposure limit hour short term limit levels immediately dangerous life health considered industrial health hazard furthermore reports related adverse reactions rare general rigorous cause effect relationships established evidence numerous radioactive common released product mainly nuclear plants nuclear weapons tests 1950s 1960s long half life million years decay low energy considered highly hazardous


potassium potassium chemical element symbol derived neo latin atomic number isolated ashes plants derives periodic table potassium seven elements column group metals elements group single electron outer electron shell easily removed create positive charge combines form potassium nature occurs potassium soft white metal rapidly air vigorously water generating sufficient heat hydrogen emitted reaction burning colored flame found dissolved sea water potassium weight minerals naturally occurring potassium composed radioactive traces found potassium common human body potassium similar previous element group periodic table similar energy allows sole outer electron different elements combine similar suspected proven industrial applications potassium exploit high water potassium compounds potassium heavy crop production rapidly soil potassium prevented agricultural containing potassium accounting global potassium chemical production potassium necessary function living cells transfer potassium nerve cell membranes necessary normal nerve transmission potassium excess result numerous including abnormal heart rhythm fresh fruits vegetables good sources potassium body responds influx potassium raises potassium levels shift potassium outside inside cells increase potassium kidney properties physical potassium second dense metal soft solid low melting point easily cut knife cut potassium appearance begins gray immediately exposure air flame test potassium compounds color peak chemical neutral potassium extremely stable configuration noble gas low energy potassium likely lose electron acquire positive charge gain acquire negative charge negatively charged impossible process requires little energy potassium readily atmospheric oxygen contrast second energy high removal breaks stable noble gas electronic configuration configuration potassium readily form compounds state higher potassium extremely active metal violently oxygen water air oxygen forms potassium water potassium forms potassium reaction potassium water dangerous violent character production hydrogen gas hydrogen atmospheric oxygen producing water remaining potassium reaction requires traces water potassium liquid potassium potent dry prior sensitivity potassium water air reactions elements possible atmosphere gas air free techniques potassium react mineral oil readily liquid depending concentration solutions blue yellow electrical similar liquid metals pure solution potassium slowly form reaction accelerated minute amounts transition metal reduce metal potassium preparation finely divided metals method example preparation method employs potassium compounds common state potassium potassium metal powerful reducing agent easily stable difficult reduce metal potassium readily carbon dioxide produce potassium remove traces gas air general potassium compounds excellent water owing high energy potassium water difficult possible precipitation methods include reactions acid potassium faster metals forms oxygen oxygen bonds metals species formed reaction potassium potassium potassium formed different oxygen based species especially rare formed reaction metals species contain oxygen oxygen bonds potassium oxygen compounds known react water violently forming potassium compound strong dissolve little water potassium compounds typically highly water main species water solution complexes poorly potassium include potassium potassium potassium known potassium occur naturally naturally occurring half life years stable electron capture stable beta decay decay basis common method dating rocks conventional dating method depends assumption rocks contained time formation subsequent retained minerals dated measurement concentration potassium accumulated minerals best suited dating include volcanic rock samples volcanic flows shallow dated apart dating potassium studies nutrient cycling studies potassium required life occurs natural potassium commercial salt sufficient quantity large bags radioactive source classroom demonstrations largest abundance body healthy animals people represents largest source greater human body mass decay second activity natural potassium cosmic formation distribution potassium formed lighter potassium principally created type explosive oxygen burning process formed process neon burning process potassium makes weight earth crust seventh abundant element crust 17th abundant element weight earth 20th abundant element solar system potassium concentration quarter concentration etymology potassium potassium separate entities known roman times latin element classical latin neo latin taken word turn came arabic plant ashes similar sounding english term root word potassium modern standard arabic german chemist martin discovered minerals realized product plant growth actually new element proposed german physicist chemist gilbert proposed names potassium swedish chemist advocated potassium chemical symbol english element potassium comes word refers method producing potassium placing pot ash burnt wood tree leaves adding water heating solution primarily mixture potassium plants little content rest plant major mineral content consists calcium relatively low water ancient times understood history fundamentally different substance mineral obtained experimental evidence led suggest fundamental difference potassium louis able prove difference exact chemical composition potassium compounds status chemical element potassium known include list chemical elements long time significant applications production glass soap gunpowder potassium potassium animal vegetable especially prized tend water softer texture known soft discovery potassium necessary element plants types soil lack potassium caused steep rise demand potassium wood ash fir trees initially potassium salt source discovery mineral deposits containing potassium near germany production potassium containing began industrial scale deposits discovered 1960s canada dominant producer metal potassium metal isolated england sir derived potassium newly discovered pile potassium metal isolated later year reported extraction metal mineral derivative plant salt similar technique demonstrating elements different production potassium metal shown elements took time view universally accepted geology potassium occur nature high violently water section precautions oxygen potassium common rock forming mineral granite example contains potassium average earth crust minerals found large deposits worldwide deposits layers starting deposits potassium formed organic material contact atmosphere caves good water formation larger deposits requires special environmental conditions commercial production potassium form extensive deposits ancient lake bottoms making extraction potassium environments commercially viable principal source potassium mined canada russia germany israel united_states jordan places world mined deposits located near germany deposits span great_britain germany poland located deposited middle late largest deposits found lie meters feet surface canadian province deposits located point group produced middle large mines operated 1960s pioneered technique freezing wet sands formation drive shafts main mining company corporation water dead sea israel jordan source concentration normal oceans low commercial production current prices methods separate potassium compounds method precipitation differences different temperatures separation ground salt mixture mines resulting waste stored underground mined potassium mineral ends potassium processing mineral industry refers potassium simply pure potassium metal isolated process changed little process developed industrial scale 1920s thermal method reacting potassium chemical reaction dominant method 1950s production potassium accomplished changing reaction time reaction process employing reaction potassium calcium produce potassium thermal method process reagent grade potassium metal costs pound purchased lower purity metal considerably cheaper market volatile long term storage metal difficult stored dry gas atmosphere mineral oil prevent formation surface layer potassium pressure sensitive explosive resulting explosion starts fire difficult biological role potassium eighth ninth common element mass human body adult contains total potassium body potassium calcium abundant potassium present wide variety proteins function potassium levels influence multiple processes including resting cellular membrane potential propagation action muscular cardiac tissue chemical properties larger channels pumps cell membranes differentiate actively pumping passing blocking action tone blood pressure control acid base action concentrating ability fluid balance potassium denotes maintenance total body potassium content potassium level ratio potassium concentrations narrow limits face intake meals shifts compartments levels potassium normally kept multiple mechanisms levels outside range associated increasing rate death multiple causes cardiac kidney lung diseases progress rapidly potassium levels maintained normal range average meal presents body potassium present surge causes potassium rise result prompt efficient clearance extra mechanisms potassium fatal severe common causes increased loss increased loss symptoms include muscle weakness decreased response severe cases respiratory cardiac control mechanisms potassium content tightly controlled basic mechanisms names classifications negative feedback system feed forward system system internal cell membrane transport system collectively termed external potassium system potassium system negative feedback system refers system potassium response rise potassium potassium shift cells feed forward system refers understood system potassium response potassium prior rise potassium probably initiated gut cell potassium detect potassium trigger signals system increases potassium hours daytime humans nighttime independent presence absence potassium nucleus brain central clock causes kidney peripheral clock potassium rhythmic fashion transport system moves potassium cell membrane mechanisms active pumps potassium cell passive allows potassium leak cell potassium influence fluid distribution compartments forces movement potassium cell membrane pump pump uses pump cell potassium cell creating gradient force cell membrane highly selective potassium channels crucial inside action potential triggered cite example recently discovered potassium channel makes total potassium channels determined structure species handling potassium closely connected handling potassium major positive inside animal cells major fluid filtered day involves potassium potassium likely replaced diet efficiently remainder maintain volume pressure concentration narrow limits potassium maintain potassium concentration narrow limits pumps operate potassium potassium blood small pool potassium cells thirty times large situation critical potassium potassium moved counter flow response apparent actual sink concentration potassium actively water end processing potassium twice times reaches collecting point usually potassium concentration end processing potassium time levels high potassium intake day week potassium declines mildly level potassium withheld concentration continues fall severe causes eventual death potassium moves pores cell membrane pumps gate pumps cell membrane gate open result approximately forced second pores gate kind stream million million second pores require calcium open thought calcium works reverse blocking pores groups inside mimic water takes place water solution nature charges groups inside diet detection taste potassium detected taste types taste according concentration solutions potassium taste sweet allowing moderate concentrations milk higher concentrations increasingly bitter finally taste combined bitterness high potassium solutions makes high dose potassium liquid drinks challenge adequate intake adequate potassium intake achieved eating variety foods potassium present fruits vegetables meat fish foods high potassium concentrations include dried dried milk chocolate nuts especially potatoes bamboo shoots water dried highest concentration potassium weight food processed foods contain potassium optimal intake studies indicate high potassium reduce risk possibly stroke mechanism independent blood pressure guidelines institute medicine specify reference intake potassium americans consume half day likewise european_union particular germany italy insufficient potassium intake somewhat common analysis concluded increase daily intake potassium associated lower risk stroke intake low potassium lead potassium widely conjunction block water upstream loop promotes increased tubular potassium resultant increased potassium variety counter available potassium dissolved water bitter taste liquid typical range potassium available formulated allow potassium slowly matrix high concentrations potassium occur adjacent solid tablet reason non potassium pills limited law maximum potassium site potassium individuals impaired kidney function risk potassium restricted severe severe restriction necessary avoid applications potassium essential component plant nutrition found soil types agriculture culture form agricultural consume global potassium chemical production potassium supplied potassium content plants range harvested weight crops conventionally expressed modern high yield agriculture depends replace potassium lost harvest agricultural contain potassium potassium sensitive crops crops needing higher content produced complex minerals contain potassium world potassium production consumed industry food potassium nutrient necessary human life health potassium seeking control lists paste orange juice white beans potatoes sources potassium ranked descending order according potassium content potassium salt main constituent powder mirrors potassium strong improve strength rise height potassium food example wine beer making straw industrial major potassium chemicals potassium potassium potassium potassium compounds produced annually potassium strong base industry strong weak control manufacture potassium industrial reactions example potassium obtained natural sources manufactured process gunpowder black powder important agricultural potassium dissolve copper precious metals particular silver gold forming complexes applications include gold mining metals organic synthesis potassium manufacture glass soap color tubes lamps textile potassium substance production potassium added matches explosives potassium photography potassium bright yellowish red color explosives fireworks leather fly paper safety matches uses properties potassium niche uses thousands uses potassium compounds example potassium orange solid acts portable source oxygen carbon dioxide widely systems mines submarines spacecraft takes volume oxygen example potassium artist pigment yellow laboratory uses potassium liquid heat transfer medium producing dry air free lowest melting point metallic compound metallic potassium types precautions potassium metal violently water producing potassium hydrogen gas reaction releases heat resulting hydrogen presence oxygen possibly potassium strong destroys living tissue causes skin burns finely potassium air room temperature bulk metal air heated density burning potassium water atmospheric oxygen common fire agents including water ineffective potassium fire worse nitrogen table salt ash dioxide sand effective dry class dry powder designed metal fires effective agents fire oxygen cool potassium metal potassium violently presence acid potassium forms react violently organic compounds react metallic potassium potassium water air usually stored mineral oil unlike potassium stored oil longer months oxygen free atmosphere vacuum prolonged storage air dangerous shock sensitive form metal lid container detonate opening highly nature potassium metal handled great care skin eye protection explosion resistant barrier user metal large amounts potassium compounds lead strongly influencing system potassium united_states lethal injection executions