Qhov sib txawv tseem ceeb ntawm ionic thiab covalent bonds yog tias ionic bonds tshwm sim ntawm cov atoms muaj qhov sib txawv ntawm electronegativities whereas covalent bonds tshwm sim ntawm atoms uas zoo sib xws los yog tsawg heev electronegativity sib txawv.
Raws li tau hais los ntawm American chemist G. N. Lewis tau hais tias 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. Ionic thiab covalent daim ntawv cog lus yog ob hom tshuaj loj, uas txuas cov atoms hauv cov tshuaj lom neeg.
Ionic Bonds yog dab tsi?
Atoms tuaj yeem nce lossis poob electrons thiab tsim cov khoom tsis zoo lossis qhov zoo; uas peb hu ua ions. Muaj kev sib cuam tshuam electrostatic ntawm cov ions. Ionic daim ntawv cog lus yog lub zog txaus nyiam ntawm cov ions sib txawv. Cov electronegativities ntawm cov atoms nyob rau hauv ib tug ionic daim ntawv cog lus feem ntau cuam tshuam lub zog ntawm electrostatic kev sib cuam tshuam ntawm ions.
Daim duab 01: Tsim cov Ionic Bond ntawm Sodium thiab Chlorine Atoms
Electronegativity yog ib qho kev ntsuas ntawm cov atoms 'affinity rau electrons. Ib qho atom, nrog cov electronegativity siab tuaj yeem nyiam cov khoom siv hluav taws xob los ntawm lub atom uas tsis tshua muaj electronegativity los tsim ib daim ntawv cog lus ionic. Piv txwv li, sodium chloride muaj ionic bond ntawm sodium ion thiab chloride ion. Sodium yog hlau thiab chlorine yog nonmetal; Yog li ntawd, nws muaj tsawg heev electronegativity (0.9) piv rau Chlorine (3.0). Vim tias qhov sib txawv ntawm electronegativity no, Chlorine tuaj yeem nyiam electron los ntawm Sodium thiab daim ntawv Cl– Tib lub sijhawm, sodium forms Na+ ions. Vim li no, ob lub atoms tau txais qhov ruaj khov noble roj hluav taws xob hluav taws xob teeb tsa. Cl– thiab Na+tau tuav ua ke los ntawm cov hluav taws xob zoo nkauj, yog li tsim ib daim ntawv cog lus ionic; Na-Cl daim ntawv cog lus.
Covalent Bonds yog dab tsi?
Thaum ob lub atoms, muaj qhov sib xws los yog tsawg heev electronegativity sib txawv, hnov qab ua ke, lawv tsim ib daim ntawv cog lus los ntawm kev sib koom electrons. Ua li no, ob lub atoms tuaj yeem tau txais cov roj hluav taws xob hluav taws xob zoo los ntawm kev sib koom electrons. Molecule yog cov khoom lag luam uas tshwm sim los ntawm kev tsim cov khoom sib txuas ntawm cov atoms. Piv txwv li, atoms ntawm tib lub ntsiab koom ua ke los tsim cov molecules xws li Cl2, H2, los yog P4, txhua lub atom khi nrog lwm tus ntawm covalent daim ntawv cog lus.
Daim duab 02: Covalent Bonds Ntawm Carbon thiab Hydrogen Atoms hauv Methane Molecule
Methane molecule (CH 4) kuj muaj covalent bonds ntawm carbon thiab hydrogen atoms; muaj plaub covalent bonds ntawm ib lub hauv paus carbon atom thiab plaub hydrogen atoms (plaub C-H bonds). Methane yog ib qho piv txwv ntawm cov molecule uas muaj covalent bonds ntawm atoms uas tsis tshua muaj electronegativity sib txawv.
Qhov txawv ntawm Ionic thiab Covalent Bonds yog dab tsi?
Ionic vs Covalent Bonds |
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| Ib qho tshuaj txuas ntawm ob lub atom tshwm sim los ntawm lub zog electrostatic ntawm qhov sib txawv-them ions hauv ib qho ionic compound. | Ib qho tshuaj txuas ntawm ob lub atom lossis ions uas cov khoom siv hluav taws xob sib koom ntawm lawv. |
| Number of Atoms | |
| Ua tshwm sim ntawm cov hlau thiab nonmetals. | Feem ntau tshwm sim ntawm ob lub nonmetals. |
| Number of Electrons | |
| Kev hloov pauv ntawm cov hluav taws xob ua tiav tshwm sim. | Ua tshwm sim thaum ob (lossis ntau dua) cov khoom sib koom electrons. |
| Sib tov | |
| Feem ntau pom zoo li cov muaju, nyob rau hauv uas ob peb qhov zoo ions nyob ib puag ncig ib qho tsis zoo ion. | Cov atoms sib raug zoo los ntawm covalent bonds muaj xws li molecules, uas nyob rau hauv chav tsev kub, feem ntau muaj nyob rau hauv gases los yog kua. |
| Polarity | |
| Ionic daim ntawv cog lus muaj qhov polarity siab. | Covalent bonds muaj qhov polarity tsawg. |
| Physical Properties | |
| Ionic tebchaw muaj cov ntsiab lus melting siab heev thiab cov ntsiab lus kub, piv rau covalent molecules. | Covalent molecules muaj cov ntsiab lus melting tsawg thiab kub kub piv rau cov ionic compounds. |
| dej solubility | |
| Nyob rau hauv polar solvents (xws li dej), ionic compounds dissolve tso ions; cov kev daws teeb meem no muaj peev xwm ua tau hluav taws xob. | Nyob rau hauv polar solvents, covalent molecules tsis yaj considerably; yog li cov kev daws teeb meem no tsis muaj peev xwm ua hluav taws xob. |
Summary – Ionic vs Covalent Bonds
Ionic thiab covalent bonds yog ob hom tshuaj lom neeg uas muaj nyob hauv cov tebchaw. Qhov sib txawv ntawm ionic thiab covalent daim ntawv cog lus yog tias ionic bonds tshwm sim ntawm cov atoms muaj qhov sib txawv ntawm electronegativities whereas covalent bonds tshwm sim ntawm atoms uas zoo sib xws los yog tsawg heev electronegativity sib txawv.
