Qhov sib txawv tseem ceeb ntawm cov hlau thiab cov hlau hnyav yog cov hlau hnyav muaj qhov ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntu
Hlau yog cov khoom siv uas muaj lub ntsej muag ci thiab ua hluav taws xob thiab cua sov kuj zoo. Piv rau tsis yog thiab metalloids, cov hlau muaj lub siab ntom ntom, muaj cov hlau hluav taws xob, thiab lwm yam yog cov qauv ntau, thiab cov tes taw.
Hlau yog dab tsi?
A hlau yog cov khoom siv uas muaj lub ntsej muag zoo nkauj heev thaum polished, tawg lossis npaj tshiab thiab muaj thermal conductivity thiab hluav taws xob. Peb tau siv cov hlau ntev heev. Kub thiab tooj liab yog thawj cov hlau uas tau pom. Tib neeg siv cov hlau no los ua cov cuab yeej, jewellery, pej thuam, thiab lwm yam. Tam sim no, nyob ib ncig ntawm 95 hom hlau sib txawv.
Daim duab 01: Txoj hauj lwm ntawm cov hlau nyob rau hauv Lub Sij Hawm Lub Sijhawm
Hlau tseem ceeb heev vim lawv cov yam ntxwv tshwj xeeb. Lawv feem ntau nyuaj thiab muaj zog (tseem muaj kev zam rau qhov no xws li sodium. Sodium tuaj yeem txiav los ntawm riam). Mercury yog cov hlau uas nyob hauv lub xeev ua kua. Tsuas yog mercury, tag nrho lwm cov hlau tshwm sim hauv lub xeev cov khoom. Hauv kev sib piv rau lwm cov khoom tsis yog hlau, nws yog ib qho nyuaj rau rhuav tshem cov hlau los yog hloov lawv cov duab. Tsis tas li ntawd, cov ntaub ntawv no muaj lub ntsej muag ci, thiab feem ntau ntawm lawv muaj ci ci ci (tshwj tsis yog kub thiab tooj liab). Txij li thaum qee cov hlau muaj zog heev nrog cov pa cua zoo li cov pa oxygen, lawv yuav tau txais cov xim npub dhau sijhawm. Nws yog feem ntau yog los ntawm kev tsim cov hlau oxide txheej. Txawm li cas los xij, cov hlau zoo li kub thiab platinum yog qhov ruaj khov thiab tsis muaj zog. Feem ntau, hlau yog malleable thiab ductile, uas tso cai rau lawv siv los ua tej yam cuab yeej.
Daim duab 02: Nails Ua los ntawm Hlau
Metallic Bonding
Tsis tas li ntawd, hlau yog atoms, uas tuaj yeem tsim cations los ntawm kev tshem tawm cov electrons. Yog li ntawd, lawv yog electropositive. Peb hu cov hom kev sib cog lus uas tsim ntawm cov atoms li kev sib txuas ntawm hlau. Nyob rau hauv cov ntaub ntawv no, cov khoom tso tawm electrons los ntawm lawv lub plhaub sab nrauv thiab cov electrons tau tawg ntawm cov hlau cations. Yog li ntawd, lawv lub npe hu ua lub hiav txwv ntawm delocalized electrons. Peb hu cov electrostatic kev sib cuam tshuam ntawm cov electrons thiab cations li "metallic bond". Cov electrons tuaj yeem txav tau; Yog li ntawd, hlau muaj peev xwm ua tau hluav taws xob. Ntxiv mus, lawv yog cov zoo thermal conductors. Vim yog kev sib txuas ntawm cov hlau, cov hlau muaj cov qauv txiav txim ib yam. Cov ntsiab lus melting siab thiab cov ntsiab lus kub ntawm cov ntaub ntawv no kuj yog vim qhov kev sib txuas ntawm cov hlau muaj zog.
Havy Hlau yog dab tsi?
Cov hlau hnyav yog ib hom hlau uas muaj qhov sib piv siab heev, cov lej atomic, thermal thiab hluav taws xob conductivity, thiab lwm yam. Cov hlau hnyav kuj muaj xws li hlau lossis hlau. Cov no suav nrog cov hlau hloov pauv, actinides, thiab lanthanides. Qee qhov piv txwv muaj xws li antimony, arsenic, bismuth, cadmium, cerium, chromium, cob alt, tooj liab, gallium, kub, hlau, lead, manganese, mercury, npib tsib xee, platinum, nyiaj, tellurium, thallium, tin, uranium, vanadium, thiab zinc.
Daim duab 03: Bismuth yog Hnyav Hlau
Cov hlau hnyav tshwj xeeb yog paub txog lawv cov tshuaj lom. Hauv peb ib puag ncig, muaj me me ntawm cov ntsiab lus no. Tsis tas li ntawd, nws yog ib qho tsim nyog yuav tsum muaj qee yam ntawm cov hlau hnyav hauv peb cov khoom noj kom muaj kev noj qab haus huv. Txawm li cas los xij, qhov loj ntawm cov hlau hnyav ua rau muaj tshuaj lom thiab tuaj yeem ua rau muaj kev puas tsuaj ntau rau cov kab mob nyob. Piv txwv li, nws tuaj yeem ua rau txo qis kev puas siab puas ntsws lossis ua rau nws puas tsuaj.
Tsis tas li ntawd, nws tuaj yeem ua rau lub ntsws, lub raum, daim siab thiab lwm yam kabmob tseem ceeb. Cov hlau hnyav zoo li sib sau ua ke hauv cov kab mob muaj sia hla cov khoom noj. Peb hu qhov no "bioaccumulation". Yog li ntawd, nws yog ib qho tseem ceeb kom paub qhov chaw ntawm cov hlau hnyav thiab tswj lawv tso tawm rau ib puag ncig ntuj.
Qhov txawv ntawm Hlau thiab Hnyav Hlau yog dab tsi?
A hlau yog cov khoom siv uas muaj lub ntsej muag zoo nkauj heev thaum polished, tawg lossis npaj tshiab thiab muaj thermal conductivity thiab hluav taws xob. Cov hlau hnyav yog hom ntawm cov hlau uas muaj qhov sib txawv heev, thiab lwm yam khoom siv hluav taws xob muaj ntau yam hnyav, thiab cov khoom siv atomic rau lwm yam hlau.
Kev toxicity yog lwm qhov sib txawv loj ntawm cov hlau thiab cov hlau hnyav. Qee cov hlau tuaj yeem ua rau muaj tshuaj lom thaum lwm tus tsis yog, tab sis cov hlau hnyav tuaj yeem ua rau muaj tshuaj lom thaum muaj ntau dua. Ntxiv mus, hlau tsis bioaccumulate yooj yim, tab sis hnyav hlau ua.
Summary – Hlau vs Heavy Metal
Qee cov hlau yog cov hlau hnyav. Tus yuam sij sib txawv ntawm cov hlau thiab hnyav yog tias cov hlau uas hnyav muaj qhov tseem ceeb heev, cov kab mob atomic hnyav lossis cov lej atomic piv rau lwm cov hlau. Tsis tas li ntawd, cov hlau hnyav hnyav piv rau lwm cov hlau thiab tuaj yeem tau txais bioaccumulated yooj yim.
