Tawm ntawm 118 lub ntsiab lus paub rau txiv neej, 94 yog hlau. Cov no yog cov ntsiab lus uas tsim cov khoom yooj yim nrog cov yam ntxwv brilliance, siab plasticity thiab malleability. Lwm yam khoom siv hlau muaj dab tsi? Lawv muab faib ua pab pawg twg? Cia peb kawm.
Hlau thiab lawv cov khoom
Kev piav txog cov hlau tsis yooj yim. Lawv nyuaj rau kev sib piv nrog lwm cov ntsiab lus lossis cov khoom paub hauv lub ntiaj teb niaj hnub no. Nyob rau hauv tus txheej txheem kev txiav txim siab, hlau yog ib tug khoom grey khoom nrog ib tug muaj zog luster. Tab sis txhua yam yog ntau nyuaj. Feem ntau ntawm lawv yog grey tiag tiag, tab sis qhov ntxoov ntxoo txawv rau txhua tus. Gallium yog xiav, bismuth yog liab, tooj liab yog ci liab, tab sis cesium, strontium thiab kub muaj xim daj.
Metals txawv heev nyob rau hauv cov nqe lus ntawm cov degree ntawm manifestation ntawm lawv cov khoom. Tiamsis muaj tej yam zoo uas koom ua ke. Cov hlau pub electrons kuj yooj yim rau sab nrauv, vim lawv tsis muaj zog ua ke rau lub nucleus ntawm ib lub atom. Lawv cov qauv sab hauv yog sawv cev los ntawm ib lub lattice siv lead ua, yog li ntawd, nyob rau hauv ib txwm muaj mob, lawv tag nrho cov khoom. Tsuas yog qhov tshwj xeeb yog mercury, uas tsuas yog hardens ntawm qhov kub thiab txias hauv qab -38.83°C.
Hlau yog cov khoom siv hluav taws xob zoo tshaj plaws ntawm cov cua sov thiab hluav taws xob. Ntau yam ntawm lawv yog cov yas heev, xws li kub, tooj liab, ntshiab chromium, nyiaj. Lawv muaj peev xwm khoov los yog crumple tsis tawg. Lwm yam yog nkig heev (manganese, tin, bismuth).
Metal pawg
Nyob rau tib lub sijhawm, cov hlau coj txawv txawv, uas tuaj yeem pom hauv qhov piv txwv ntawm mercury. Nws ua kua tau yooj yim heev, tab sis tsis yog txhua yam khoom coj mus rau tib txoj kev. Nyob ntawm qhov chaw melting, fusible thiab refractory hlau yog txawv. Cov tom kawg suav nrog tungsten, tantalum, rhenium, molybdenum. Lawv yaj ntawm qhov kub siab tshaj 2000 ° C.
Cov hlau hnyav thiab lub teeb kuj txawv. Hnyav - txhuas, cadmium, cob alt, mercury, tooj liab, vanadium, muaj qhov hnyav atomic loj (ntau tshaj 50) thiab siab ceev. Lub ntsws yog qhov sib txawv. Cov no suav nrog aluminium, gallium, indium. Lithium yog lub teeb tshaj plaws, nrog qhov ceev ntawm 0.533 g / cm³ thiab atomic loj ntawm 3.
Nyob rau hauv Lub Sijhawm Lub Sijhawm, pawg alkaline ntawm cov hlau (lithium, sodium, potassium, rubidium) kuj txawv. Lawv hnov mob yooj yim heev nrog dej los tsim cov alkali soluble lossis hydroxide. Tag nrho cov ntawm lawv yog heev nquag, mos thiab ntau lighter tshaj dej. Kuj tseem muaj alkaline ntiaj teb hlau (calcium, barium, strontium), alkali nrog dej twb tsim lawv cov oxides los yog lub ntiaj teb. Lawv nyuaj dua thiab tsis ua haujlwm zoo li cov alkaline.
Raws li cov khoom sib txawv ntawm cov hlau, lawv kuj tau muab faib ua:
- Kev hloov pauv.
- Post transitional.
- xim.
- Black.
- Lanthanides.
- Actinides.
- Noble.
- Platinum pab pawg hlau.
- Rare earth.
Precious Metals
Hlau feem ntau ua raws li kev txo cov tshuaj hauv cov tshuaj tiv thaiv. Los ntawm kev muab lawv cov electrons, lawv raug cov txheej txheem corrosive uas ua rau lawv puas tsuaj. Nyob rau hauv qhov kev txiav txim ntawm oxidizing agents, oxides, hydroxides, yog tsim rau ntawm lawv nto, uas yog nrov hu ua xeb.
Ntau cov hlau raug rau cov txheej txheem zoo li no. Destroyers rau lawv tuaj yeem yog gases thiab ntau yam kua. Txawm li cas los xij, muaj ib chav sib cais ntawm cov hlau uas ua tau zoo rau oxidation thiab xeb. Cov no yog cov hlau noble. Tag nrho cov ntawm lawv kuj tsis tshua muaj nqi. Lawv cov nqi ntawm $300 (nyiaj) txog $70,000 (rhodium) ib kilo.
Noble yog kub, nyiaj, thiab platinum pab pawg hlau: platinum, ruthenium, osmium, palladium, iridium, rhodium. Platinum, palladium, kub thiab nyiaj yog cov yas heev, tab sis lawv tsis tuaj yeem tiv taus qhov kub thiab txias. Tag nrho cov noble hlau kuj yog refractory, melting ntawm 2334 ° C (ruthenium) mus rau 3033 ° C (osmium).
Txhua tus ntawm lawv tuaj yeem tiv taus dej thiab huab cua, tab sis tuaj yeem cuam tshuam nrog cov khoom hnyav dua. Piv txwv li, nyiaj dissolves yooj yim hauv nitric acid, thiab darkens thaum nws los rau hauv kev sib cuag nrog iodine. Los ntawm txoj kev, nrog kev pab ntawm iodine, koj tuaj yeem tshawb xyuas seb cov khoom puas yog nyiaj tiag tiag.
Nyob hauv ntuj
Hlau yog dav hauv peb lub ntiaj teb. nyob rau hauv daim ntawv ntawm ntsev thiabcompounds lawv muaj nyob rau hauv dej hiav txwv. Feem ntau ntawm tag nrho cov, nws yog tag nrho ntawm magnesium (0.12%) thiab calcium (1.05%). Cov hlau ntau tshaj plaws nyob rau hauv lub ntiaj teb crust yog aluminium. Nws ua txog li 8% ntawm tag nrho nws pawg. Nws kuj tseem muaj hlau (4.1%), calcium (4%), sodium (2.3%), magnesium (2.3%), potassium (2.1%).
Tab sis cov hlau tsis yog nyob hauv ib puag ncig sab nraud xwb. Lawv muaj nyob rau hauv txhua yam kabmob muaj sia, lub luag haujlwm rau ntau lub luag haujlwm tseem ceeb. Tib neeg lub cev muaj li 3% ntawm cov hlau. Hlau nyob rau hauv cov ntshav pab hemoglobins txuas oxygen thiab pauv nrog carbon dioxide. Magnesium muaj nyob rau hauv cov leeg thiab lub paj hlwb. Nws koom nrog hauv kev sib txuas ntawm cov protein, yog lub luag haujlwm rau cov leeg nqaij so, inhibits excitation ntawm paj hlwb.
Qhov tsim nyog tshaj plaws rau peb: magnesium, hlau, sodium, calcium, potassium, zinc, tooj liab, cob alt, manganese thiab molybdenum. Cov hlau muaj nyob hauv cov pob txha, hauv lub hlwb, hauv cov ntaub so ntswg ntawm lwm yam kabmob. Peb tau txais lawv los ntawm dej thiab zaub mov, thiab tas li yuav tsum tau ntxiv lawv cov khoom lag luam. Nrog rau qhov tsis txaus ntawm cov ntsiab lus no, lub cev tsis ua haujlwm zoo, txawm li cas los xij, lawv qhov ntau dhau kuj tsis zoo.
Daim ntawv thov
Tib neeg tau kawm siv hlau hauv yuav luag txhua qhov chaw ntawm lawv lub neej. Cov ntaub ntawv tsim qauv, xov hlau, hluav taws xob engineering, tais diav yog tsim los ntawm lawv. Cov khoom siv hluav taws xob tsis ruaj khov xws li uranium, californium, polonium tau pom siv hauv nuclear fais fab thiab riam phom tsim.
Lub teeb thiab muaj zog hlau yog siv hauv qhov chaw thev naus laus zis thiab kev lag luam tsheb. Ntau yam khoom siv hauvtshuaj, zaub mov thiab textile kev lag luam. Lawv siv los ua cov hniav nyiaj hniav kub, khoom siv hauv tsev, nrog rau cov tshuaj thiab cov cuab yeej kho mob. Lithium, piv txwv li, yog siv los ua cov tshuaj tiv thaiv kev nyuaj siab, kub muaj nyob rau hauv kev kho mob rau mob caj dab thiab tuberculosis. Titanium thiab tantalum yog siv rau hauv kev phais los ua cov prostheses thiab hloov qhov puas ntawm lub cev.
