1. Muab ib daim av nplaum, cia cov menyuam kawm ntawv saib nws, tawg tawm ntawm nruab nrab (ceev faj tsis txhob zom cov ntoo khaub lig), thiab tom qab ntawd txuas ob daim av nplaum ua ke. Tuav ob qhov kawg ntawm cov av nplaum thiab nyem, kom lub zog muaj zog ntawm cov stubble, thiab maj mam tso tawm, ob ntu tuaj yeem ua ke ua ke, thiab tuav ib qho kawg los qhia cov tub ntxhais kawm. Thaum nws tau shaken maj mam, nws yuav tsis tawg dua, uas yog txaus los qhia tias muaj ib tug attraction ntawm molecules (vim chalk yog qhuav thiab tsis yog - cov khoom nplaum, nws yuav tsis ua rau cov tub ntxhais kawm to taub yuam kev xws li plasticine). Kev sau ntawv rau ntawm daim ntawv dub nrog chalk qhia tau hais tias tseem muaj lub zog gravitational ntawm lub blackboard thiab chalk molecules, yog li nws tuaj yeem pom tau tias lub zog intermolecular gravitational tsis tsuas yog nyob nruab nrab ntawm tib hom molecules, tab sis kuj ntawm ntau hom molecules.
2. Tig lub chalk ntawm lub kaum sab xis thiab nias nws dua, nws tsis yooj yim rau ntes. Qhov laj thawj yog vim li cas feem ntau ntawm qhov sib txawv ntawm cov molecular ntau dua 10r0, thiab tsis muaj ntau qhov sib txawv ntawm molecular ze rau 10r0, yog li lub zog gravitational tsis txaus rau ua kom lawv haum ua ke, yog li nws tuaj yeem pom tau tias qhov sib nrug ntawm molecular ntau dua li Lub zog molecular yog negligible ntawm 10r0.
3. Siv yooj yim-rau-nrhiav chalk kom ib txhij qhia txog qhov muaj zog gravitational ntawm cov molecules thiab cov xwm txheej nyob rau hauv uas molecular rog yuav tsis quav ntsej. Tsis tas li ntawd, qhov kev sim tuaj yeem ua tiav ua ke nrog cov tub ntxhais kawm, sau cov ntsiab lus thaum sim, thiab chav kawm paub daws teeb meem thiab dhuav tuaj yeem ua tiav hauv qhov chaw so thiab nquag.
