Qhov Tseem Ceeb Qhov Sib Txawv - Adhesive vs Cohesive Forces
Adhesive rog ua rau qhov sib txawv ntawm qhov sib txawv kom tau txais kev sib nyiam. Adhesive rog tuaj yeem yog cov khoom siv hluav taws xob uas ua rau cov molecules los ua ke los yog tuaj yeem yog electrostatic zog uas muaj nyob nruab nrab ntawm qhov zoo thiab qhov tsis zoo. Cohesive rog muaj nyob nruab nrab ntawm qhov chaw zoo sib xws. Yog li ntawd, cov rog no ua rau tsim cov pawg ntawm cov molecules zoo sib xws. Cohesive rog tuaj yeem yog hydrogen bonds lossis Van der Waal rog. Hydrogen bonds tshwm sim ntawm polar molecules uas muaj O-H, N-H, thiab F-H pawg. Van der Waal rog muaj nyob nruab nrab ntawm nonpolar molecules. Qhov sib txawv tseem ceeb ntawm Adhesive thiab Cohesive Forces yog tias cov nplaum nplaum muaj nyob nruab nrab ntawm cov molecules sib txawv thaum lub zog cohesive muaj nyob ntawm cov molecules zoo sib xws.
Adhesive Forces yog dab tsi?
Adhesive rog yog lub zog nruab nrab uas muaj nyob nruab nrab ntawm qhov sib txawv ntawm qhov chaw. Nws yog macroscopic khoom ntawm cov khoom. Adhesion yog qhov sib txuas ntawm ib qho chaw mus rau lwm qhov chaw uas ob qhov chaw sib txawv ntawm ib leeg. Yog li ntawd, cov nplaum nplaum yog lub zog txaus nyiam uas muaj nyob nruab nrab ntawm qhov tsis zoo li molecules.
Adhesive rog tuaj yeem yog lub zog siv hluav taws xob lossis hluav taws xob hluav taws xob. Mechanical quab yuam ua rau cov khoom sib txuas ua ke whereas electrostatic rog ua rau muaj kev cuam tshuam ntawm ob qhov sib txawv; cov nqi zoo thiab cov nqi tsis zoo. Tsis tas li ntawd xwb, muaj zog diffusive thiab dispersive zog uas yuav ua rau adhesion los yog nplaum rog.
Lub zog ntawm cov nplaum nplaum ntawm ob, tsis zoo li qhov chaw, nyob ntawm lub tshuab uas lub nplaum yuav tshwm sim thiab thaj chaw saum npoo uas cov nplaum nplaum ua rau. Lub zog saum npoo ntawm cov khoom txiav txim siab muaj peev xwm ntub dej rau ib leeg. Piv txwv li, ib yam khoom xws li polyethylene muaj lub zog qis. Yog li ntawd, nws yuav tsum tau npaj tshwj xeeb saum npoo ua ntej tsim cov nplaum nplaum.
Daim duab 01: A Meniscus
Cia peb xav txog ib qho piv txwv txog cov nplaum nplaum. Lub meniscus yog qhov tsim ntawm cov kua dej uas tuaj yeem pom hauv cov kua thaum cov kua ntim rau hauv lub thawv. Rau kev tsim cov meniscus, ob qho tib si cohesive thiab nplaum nplaum yuav tsum tau. Nyob ntawd, cov nplaum nplaum ntawm cov kua molecules thiab qhov chaw ntawm lub thawv ua rau cov npoo ntawm cov kua nyob rau ntawm theem siab tshaj qhov nruab nrab ntawm cov kua (tsim ntawm concave).
Cohesive Forces yog dab tsi?
Cohesive rog yog intermolecular rog uas muaj nyob nruab nrab ntawm qhov zoo sib xws ntawm qhov chaw. Nws yog macroscopic khoom ntawm cov khoom. Cohesion yog cov txheej txheem ntawm cov molecules zoo sib xws ua ke. Cov rog intermolecular uas ua rau muaj kev sib koom ua ke tuaj yeem yog hydrogen bonds lossis Van der Waal attraction rog. Cohesion tuaj yeem txhais tau tias yog qhov nyiam ntawm cov kua dej sib cais.
Daim duab 02: Mercury nthuav tawm Kev Sib Koom Tes
Cohesive rog ua rau cov molecules ntawm tib yam khoom sib sau ua ke, tsim pawg. Piv txwv li, nag los ua dej ntws. Qhov no yog vim lub cohesive rog uas muaj nyob nruab nrab ntawm dej molecules. Cov rog no ua rau tsim cov dej molecule pawg. Cov dej molecule muaj polarization; muaj ib nrab nqi zoo thiab ib nrab nqi tsis zoo nyob rau hauv tib molecule. Cov nqi zoo ntawm cov dej molecules yog attracted rau qhov tsis zoo nqi ntawm cov nyob sib ze molecules.
Qhov txawv ntawm Adhesive thiab Cohesive Forces yog dab tsi?
Adhesive vs Cohesive Forces |
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| Adhesive rog yog lub zog nruab nrab uas muaj nyob nruab nrab ntawm qhov sib txawv ntawm qhov chaw. | Cohesive rog yog intermolecular rog uas muaj nyob nruab nrab ntawm qhov zoo sib xws ntawm qhov chaw. |
| Ncua zog | |
| Adhesive rog muaj nyob nruab nrab ntawm cov molecules sib txawv. | Cohesive rog muaj nyob nruab nrab ntawm cov molecules zoo sib xws. |
| Type of Attraction Force | |
| Adhesive rog tuaj yeem yog lub zog siv hluav taws xob lossis hluav taws xob hluav taws xob. | Cov rog sib xyaw ua ke tuaj yeem yog hydrogen bonds lossis Van der Waal attraction rog. |
Summary – Adhesive vs Cohesive Forces
Adhesive rog yog cov quab yuam uas tuaj yeem yog cov khoom siv hluav taws xob lossis hluav taws xob hluav taws xob. Cohesive rog tuaj yeem yog hydrogen bonds lossis Van der Waal attractions. Qhov sib txawv ntawm cov nplaum nplaum thiab cov rog sib xyaw yog tias cov nplaum nplaum muaj nyob nruab nrab ntawm cov molecules tsis sib xws whereas cohesive rog muaj nyob nruab nrab ntawm cov molecules zoo sib xws.
