Tam sim no, kev tshawb fawb paub txog ib puas thiab tsib yam tshuaj lom neeg, ua kom zoo nyob rau hauv daim ntawv ntawm lub sijhawm. Feem coob ntawm lawv tau muab cais ua cov hlau, uas txhais tau hais tias cov khoom no muaj qhov tshwj xeeb zoo. Cov no yog cov khoom hu ua hlau. Cov yam ntxwv zoo li no, ua ntej ntawm tag nrho cov, suav nrog plasticity, nce thermal thiab hluav taws xob conductivity, muaj peev xwm tsim cov alloys, thiab muaj peev xwm ionization tsawg.
Cov khoom siv hlau ntawm ib lub caij yog vim muaj peev xwm ntawm nws cov atoms, thaum cuam tshuam nrog cov qauv atomic ntawm lwm cov ntsiab lus, kom tshem cov huab cua hauv lawv cov kev taw qhia lossis "muab" lawv cov hluav taws xob dawb rau lawv. Cov hlau nquag tshaj plaws yog cov uas muaj ionization qis zog thiab electronegativity. Tsis tas li ntawd, pronounced metallic zog yog cov yam ntxwv ntawm cov khoom uas muajqhov loj tshaj plaws atomic radius thiab qhov tsawg tshaj plaws tau ntawm sab nraud (valence) electrons.
Raws li lub valence orbit puv, tus naj npawb ntawm electrons nyob rau hauv txheej txheej ntawm lub atomic qauv nce, thiab lub vojvoog, raws li, txo. Hauv qhov no, cov atoms pib siv zog rau kev txuas ntawm cov hluav taws xob dawb, thiab tsis yog rau lawv rov qab los. Cov khoom siv hlau ntawm cov khoom zoo li no yuav txo qis, thiab lawv cov khoom tsis yog xim hlau yuav nce ntxiv. Hloov pauv, nrog kev nce hauv lub vojvoog atomic, qhov nce hauv cov khoom siv hlau tau sau tseg. Yog li ntawd, ib tug yam ntxwv zoo ntawm tag nrho cov hlau yog lub thiaj li hu ua txo qualities - lub peev xwm heev ntawm ib tug atom los pub dawb electrons.
Cov khoom siv hlau zoo tshaj plaws ntawm cov ntsiab lus tau tshwm sim hauv cov khoom ntawm thawj, ob pawg ntawm pawg loj ntawm lub rooj zaum, nrog rau hauv alkali thiab alkaline ntiaj teb hlau. Tab sis qhov muaj zog txo qis zog yog pom nyob rau hauv francium, thiab nyob rau hauv cov dej ib puag ncig - nyob rau hauv lithium vim lub zog hydration ntau dua.
Tus naj npawb ntawm cov khoom uas pom cov khoom siv hlau nyob hauv ib lub sijhawm nce nrog lub sijhawm tus lej. Nyob rau hauv lub sij hawm lub sij hawm, cov hlau yog sib cais los ntawm cov hlau tsis muaj hlau los ntawm ib tug kab pheeb ces kaum uas khiav los ntawm boron mus rau astatin. Nyob rau hauv txoj kab sib faib no muaj cov ntsiab lus uas ob qho tib si zoo sib xws. Cov tshuaj xws li silicon, arsenic, boron, germanium, astatine, antimonythiab tellurium. Cov pawg no hu ua metalloids.
Txhua lub sijhawm yog tus yam ntxwv los ntawm qhov muaj ib hom "ciam ciam teb" nyob rau hauv cov ntsiab lus nrog ob qhov zoo nyob. Yog li ntawd, kev hloov pauv ntawm cov lus hais rau cov hlau tsis zoo yog maj mam, uas tau tshwm sim nyob rau hauv lub rooj zaum.
Cov khoom siv dav dav ntawm cov hlau hlau (siab hluav taws xob conductivity, thermal conductivity, malleability, yam ntxwv luster, plasticity, thiab lwm yam) yog vim qhov zoo sib xws ntawm lawv cov qauv sab hauv, los yog es, muaj ib tug siv lead ua lattice. Txawm li cas los xij, muaj ntau yam zoo (qhov ntom, hardness, melting point) uas muab tag nrho cov hlau ua ib tus neeg lub cev thiab tshuaj lom neeg. Cov yam ntxwv no nyob ntawm seb cov qauv ntawm cov siv lead ua lattice ntawm txhua qhov tshwj xeeb.
