Polar vs Nonpolar
Raws li tau hais los ntawm American chemist G. N. Lewis, atoms ruaj khov thaum lawv muaj yim electrons hauv lawv lub plhaub valence. Feem ntau ntawm cov atoms muaj tsawg tshaj li yim electrons nyob rau hauv lawv valence shells (tshwj tsis yog cov noble gases nyob rau hauv pab pawg neeg 18 ntawm lub periodic rooj); yog li ntawd, lawv tsis ruaj khov. Cov atoms no zoo li ua rau ib leeg ua kom ruaj khov. Yog li, txhua lub atom tuaj yeem ua tiav cov roj hluav taws xob hluav taws xob zoo. Txhawm rau kom cov atoms tau hnov txog ib leeg, yuav tsum muaj kev nyiam. Electron txav hauv atoms lossis molecules ua rau lawv cov polar lossis nonpolar, thiab qhov no pab lawv cov kev sib cuam tshuam.
Polar
Polarity tshwm sim vim qhov sib txawv ntawm electronegativity. Electronegativity muab ib qho kev ntsuas ntawm ib lub atom kom nyiam electrons nyob rau hauv ib daim ntawv cog lus. Feem ntau Pauling nplai yog siv los qhia txog qhov tseem ceeb ntawm electronegativity. Yog tias qhov sib txawv ntawm electronegativity ntawm ob lub atoms loj heev (ntau tshaj 1.7), ces daim ntawv cog lus yuav yog ionic. Rau ib daim ntawv cog lus los ua ib tug polar, qhov sib txawv electronegativity yuav tsum tsis pub tshaj tus nqi 1.7. Nyob ntawm qhov sib txawv ntawm electronegativity, qhov polarity tuaj yeem hloov pauv. Qhov kev sib txawv no yuav siab dua lossis qis dua. Yog li, daim ntawv cog lus electron khub yog rub ntau dua los ntawm ib lub atom piv rau lwm lub atom uas koom nrog hauv kev ua daim ntawv cog lus. Qhov no yuav ua rau muaj kev faib tsis sib npaug ntawm electrons ntawm ob lub atoms. Vim tias qhov sib faib tsis sib luag ntawm cov hluav taws xob, ib lub atom yuav muaj qhov tsis zoo me ntsis thaum lwm lub atom yuav muaj qhov zoo me ntsis. Hauv qhov piv txwv no, peb hais tias cov atoms tau txais ib feem tsis zoo lossis qhov zoo. Lub atom nrog lub siab dua electronegativity tau txais qhov tsis zoo me ntsis, thiab lub atom nrog qis electronegativity yuav tau txais qhov zoo me ntsis. Polarity txhais tau tias kev sib cais ntawm cov nqi. Cov molecules no muaj lub sijhawm dipole. Dipole lub sijhawm ntsuas qhov polarity ntawm daim ntawv cog lus, thiab nws feem ntau ntsuas hauv debyes (nws kuj muaj kev taw qhia).
Polar tshuaj zoo li cuam tshuam nrog lwm yam polar.
Tsis yog-polar
Thaum ob ntawm tib lub atom lossis atoms muaj tib lub electronegativity tsim ib daim ntawv cog lus ntawm lawv, cov atoms rub cov electron khub zoo ib yam. Yog li ntawd, lawv nyiam sib koom cov electrons thiab cov nyiaj no yog hu ua nonpolar covalent bonds. Piv txwv li, thaum tib atoms koom ua ke los tsim cov molecules xws li Cl2, H2, los yog P4., txhua lub atom raug khi rau lwm tus los ntawm cov ntawv cog lus tsis muaj polar. Cov molecules no yog nonpolar molecules.
Nonpolar tshuaj nyiam cuam tshuam nrog lwm yam tsis muaj polar.
Dab tsi yog qhov txawv ntawm Polar thiab Tsis-polar?
• Polar molecules muaj lub sijhawm hluav taws xob dipole whereas nonpolar molecules tsis muaj lub sijhawm dipole.
• Polar molecules muaj cov nqi sib cais hauv qhov sib piv rau cov tsis muaj polar molecules.
• Cov tshuaj tiv thaiv kab mob zoo li cuam tshuam nrog lwm cov tshuaj polar; lawv tsis nyiam cuam tshuam nrog cov khoom tsis muaj polar.
