Dab tsi yog hlau? Qhov xwm ntawm cov khoom no tau muaj kev txaus siab txij thaum ancient sij hawm. Txog 96 hom hlau tau pom txog tam sim no. Peb yuav tham txog lawv cov yam ntxwv thiab cov khoom hauv kab lus.
Dab tsi yog hlau?
Cov ntsiab lus ntau tshaj plaws nyob rau hauv lub sij hawm lub sij hawm yog hais txog cov hlau. Tam sim no, tsuas yog 96 ntawm lawv hom paub rau txiv neej. Txhua tus muaj nws tus yam ntxwv, ntau yam uas tseem tsis tau kawm.
Dab tsi yog hlau? Qhov no yog cov khoom siv yooj yim, uas yog tus cwj pwm los ntawm cov hluav taws xob siab thiab thermal conductivity, qhov zoo kub coefficient ntawm conductivity. Cov hlau feem ntau muaj lub zog siab, ductility thiab tuaj yeem ua forged. Ib qho ntawm cov yam ntxwv sib txawv yog qhov muaj cov xim hlau.
Lub ntsiab lus ntawm lo lus "hlau" yog txuam nrog Greek métallion, qhov twg nws txhais tau tias "kom khawb tawm ntawm lub ntiaj teb", thiab "kuv, kuv". Nws tuaj rau Lavxias teb sab terminology thaum lub sij hawm reign ntawm Peter I los ntawm German lus (German Metall), uas lo lus tsiv los ntawm Latin.
Lub cev muaj zog
Cov ntsiab lus hlau feem ntau muaj qhov zoo ductility, tshwj tsis yog tin, zinc, manganese. Los ntawm qhov ntom ntom, lawv muab faib ua lub teeb(aluminium, lithium) thiab hnyav (osmium, tungsten). Feem ntau muaj cov ntsiab lus melting siab, nrog rau qhov dav dav ntawm -39 degrees Celsius rau mercury rau 3410 degrees Celsius rau tungsten.
Raws li ib txwm muaj, txhua yam hlau tshwj tsis yog mercury thiab francium yog khoom. Lub degree ntawm lawv hardness yog txiav txim nyob rau hauv cov ntsiab lus ntawm lub Moss scale, qhov siab tshaj plaws yog 10 ntsiab lus. Yog li, qhov nyuaj tshaj plaws yog tungsten thiab uranium (6.0), qhov softest yog cesium (0.2). Ntau cov hlau muaj nyiaj, xiav thiab grey tints, tsuas yog ob peb xim daj thiab liab.
Txawb electrons yog nyob rau hauv lawv cov siv lead ua lattices, ua tsaug rau lawv yog cov zoo heev conductors ntawm hluav taws xob tam sim no thiab tshav kub. Nyiaj thiab tooj liab ua haujlwm zoo tshaj nrog qhov no. Mercury muaj qhov thermal conductivity qis tshaj.
tshuaj muaj zog
Hlau tau muab faib ua ntau pawg raws li lawv cov khoom siv tshuaj. Ntawm lawv yog alkaline, alkaline ntiaj teb, lub teeb, actinium thiab actinides, lanthanum thiab lanthanides, semimetals. Magnesium thiab beryllium pom nyias.
Raws li txoj cai, cov hlau ua raws li cov neeg ua haujlwm txo qis rau cov hlau tsis yog hlau. Lawv muaj cov dej num sib txawv, yog li cov tshuaj tiv thaiv tsis zoo ib yam. Cov nquag nquag yog cov hlau alkali, lawv yooj yim cuam tshuam nrog hydrogen, dej.
Raws li qee yam xwm txheej, kev sib cuam tshuam ntawm cov hlau nrog oxygen yuav luag ib txwm tshwm sim. Tsuas yog kub thiab platinum tsis hnov mob rau nws. Lawv kuj tsis hnov mob rau sulfur thiab chlorine, tsis zoo li lwm yam hlau. Cov pab pawg alkali yog oxidized rauIb puag ncig zoo tib yam, tus so thaum raug kub hnyiab.
Nyob hauv ntuj
Nyob rau hauv qhov xwm txheej, cov hlau feem ntau pom muaj nyob rau hauv ores lossis cov tebchaw, xws li oxides, ntsev, carbonates. Lawv mus dhau cov kauj ruam tu kom ntev ua ntej yuav siv. Ntau cov hlau nrog cov pob zeb hauv av. Yog li, cadmium yog ib feem ntawm zinc ores, scandium thiab tantalum nyob ib sab ntawm tin.
Tsuas yog inert, uas yog, cov hlau tsis muaj zog, pom tam sim ntawd hauv lawv daim ntawv ntshiab. Vim lawv tsis tshua muaj kev cuam tshuam rau oxidation thiab corrosion, lawv yeej lub npe ntawm noble. Cov no muaj xws li kub, platinum, nyiaj, ruthenium, osmium, palladium, thiab lwm yam. Noble hlau yog ductile heev thiab muaj ib tug yam ntxwv ci ci nyob rau hauv cov khoom tiav.
Hlau yog nyob ib puag ncig peb. Lawv pom muaj ntau nyob rau hauv lub ntiaj teb crust. Feem ntau yog txhuas, hlau, sodium, magnesium, calcium, titanium thiab potassium. Lawv muaj nyob rau hauv dej hiav txwv (sodium, magnesium), yog ib feem ntawm cov kab mob nyob. Hauv tib neeg lub cev, hlau muaj nyob hauv cov pob txha (calcium), ntshav (hlau), paj hlwb (magnesium), cov leeg (magnesium) thiab lwm yam kabmob.
Kawm thiab siv
Ancient civilizations paub tias hlau yog dab tsi. Ntawm cov Egyptian archaeological pom hnub rov qab mus rau 3-4 txhiab xyoo BC, cov khoom ua los ntawm cov hlau muaj txiaj ntsig tau pom. Thawj tus txiv neej nrhiav tau kub, tooj, nyiaj, lead, hlau, tin, mercury. Lawv tau siv los ua cov hniav nyiaj hniav kub, cov cuab yeej, cov khoom ritual thiab riam phom.
Nyob rau hauv Nruab Nrab Hnub nyoog, antimony, arsenic, bismuth, zinc tau pom. Lawv feem ntau tau muab tej yam yees siv, txuam nrog lub cosmos, lub zog ntawm lub ntiaj chaw. Alchemists tau ua ntau yam kev sim nyob rau hauv kev cia siab ntawm tig mercury rau hauv dej los yog kub. Maj mam, tus naj npawb ntawm kev tshawb pom tau nce ntxiv, thiab los ntawm lub xyoo pua 21st, tag nrho cov hlau paub txog niaj hnub tau pom.
Tam sim no lawv tau siv hauv yuav luag txhua qhov ntawm lub neej. Cov hlau yog siv los ua cov hniav nyiaj hniav kub, khoom siv, nkoj, tsheb. Lawv yog siv los ua thav duab rau kev tsim vaj tsev, rooj tog, thiab ntau yam me me.
Cov khoom siv hluav taws xob zoo heev tau ua rau cov hlau tsis tseem ceeb rau kev tsim cov xov hlau, nws ua tsaug rau nws uas peb siv hluav taws xob tam sim no.
