Coordinate Covalent Bond vs Covalent Bond
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. Covalent daim ntawv cog lus yog ib hom tshuaj lom neeg loj uas txuas atoms hauv cov tshuaj lom neeg.
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. Nyob rau hauv lub sij hawm lub sij hawm, muaj ib tug qauv raws li yuav ua li cas lub electronegativity qhov tseem ceeb hloov. Los ntawm sab laug mus rau sab xis los ntawm ib lub sij hawm, tus nqi electronegativity nce. Yog li ntawd, halogens muaj qhov tseem ceeb ntawm electronegativity loj dua nyob rau hauv ib lub sij hawm, thiab pawg 1 cov ntsiab lus muaj qhov sib piv qis electronegativity qhov tseem ceeb. Hauv cov pab pawg, cov txiaj ntsig electronegativity txo. Thaum ob ntawm tib lub atom los yog atoms muaj tib lub electronegativity tsim ib daim ntawv cog lus ntawm lawv, cov atoms rub lub electron khub nyob rau hauv ib txoj kev zoo sib xws. Yog li ntawd, lawv nyiam sib faib cov electrons thiab cov nyiaj no yog hu ua nonpolar covalent bonds.
Covalent Bond
Thaum ob lub atoms zoo sib xws lossis qis heev electronegativity sib txawv, hnov qab ua ke, lawv tsim ib daim ntawv cog lus los ntawm kev sib koom electrons. Ob lub atoms tuaj yeem tau txais cov roj hluav taws xob hluav taws xob zoo los ntawm kev sib koom electrons hauv txoj kev no. Molecule yog cov khoom uas tshwm sim los ntawm kev tsim ntawm covalent bonds ntawm atoms. 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 covalent daim ntawv cog lus.
Coordinate Covalent Bond
Qhov no kuj yog ib hom kev sib cog lus uas ob lub tshuab hluav taws xob hauv daim ntawv cog lus tsuas yog pub dawb los ntawm ib lub atom xwb. Qhov no tseem hu ua dative bond. Hom kev sib cog lus no yog tsim thaum Lewis puag pub ib khub electron rau Lewis acid. Yog li, qhov no kuj tuaj yeem piav qhia raws li kev cog lus ntawm Lewis acid thiab Lewis puag. Hauv txoj kev xav, los qhia qhov pub dawb atom thiab tsis pub dawb, peb muab tus nqi zoo rau lub atom pub dawb thiab tus nqi tsis zoo rau lwm lub atom. Piv txwv li, thaum ammonia pub rau ib leeg electron khub ntawm nitrogen rau Barium ntawm BF 3, kev sib koom ua ke cov nyiaj tau los. Tom qab tsim, daim ntawv cog lus no zoo ib yam li daim ntawv cog lus covalent thiab tsis tuaj yeem paub qhov txawv ntawm daim ntawv cog lus txawm tias nws muaj lub npe cais.
Qhov txawv ntawm Covalent Bond thiab Coordinate Covalent Bond yog dab tsi?
• Hauv daim ntawv cog lus, ob lub atoms tau pab tib tus lej ntawm cov electrons rau daim ntawv cog lus, tab sis nyob rau hauv ib qho kev sib koom ua ke, ob lub electrons raug pub dawb los ntawm ib lub atom.
• Hauv daim ntawv cog lus covalent, qhov sib txawv ntawm electronegativity ntawm ob lub atom tuaj yeem yog xoom lossis tus nqi qis heev, tab sis hauv kev sib koom ua ke covalent daim ntawv cog lus, hom ntawm daim ntawv cog lus covalent yog tsim.
• Rau kev sib koom ua ke covalent daim ntawv cog lus, ib qho atom hauv lub molecule yuav tsum muaj ib khub.
