Hauv huab cua ntawm lub ntiaj teb no tsis muaj roj helium lossis hydrogen dawb. Tsuas muaj nitrogen (78%), oxygen (21%), argon (0,90%), carbon dioxide, thiab lwm yam. Huab cua ntawm Venus yuav luag tag nrho yog tsim los ntawm carbon dioxide (CO2)2). Lub huab cua ntawm Jupiter muaj ntau yam helium thiab hydrogen dawb. Lub hli tsis muaj huab cua. Vim li cas cov hom huab cua ntawm txhua lub ntiaj teb thiaj txawv? Vim li cas tsis muaj helium thiab hydrogen dawb hauv lub ntiaj teb huab cua?
Qhov ceev ntawm cov hauv paus nruab nrab
Qhov ceev ntawm cov hauv paus nruab nrab = qhov ceev ntawm cov hauv paus nruab nrab = vrmsPeb tuaj yeem nrhiav tau qhov sib npaug vrms los ntawm kev hloov cov qauv ntawm Kub thiab Kinetic Zog txhais lus.
Cov Ntaub Ntawv:
v rms = qhov ceev lossis qhov ceev ntawm cov hauv paus nruab nrab (m/s)
k = Boltzman tus nqi tas mus li n (k = 1,38 x 1023 J/K)
T = Qhov kub thiab txias kiag li (K = Kelvin)
m = pawg (kg)
Cov Ntaub Ntawv:
v rms = qhov ceev lossis qhov ceev ntawm lub hauv paus nruab nrab (m/s)
R = Qhov tsis hloov pauv ntawm cov pa roj thoob ntiaj teb (R = 8,315 J/mol.K = 8315 kJ/kmol.K)
NA = Tus naj npawb ntawm cov molecule ib mole = Avogadro tus lej (NA = 6,02 x 1023 /mol = 6,02 x 1026 /kmol)
T = kub (K)
M = molecular mass = molar mass (kg/kmol los yog gram/mol)
Cov vrms uas tau los saum toj no yog qhov nruab nrab ntawm cov molecules hauv cov roj. Qee cov molecules muaj qhov ceev ntau dua vrms, thaum lwm tus muaj qhov ceev me dua vrms. Xyoo 1859, James Clerk Maxwell (1831–1879) tau tshawb pom qhov kev faib tawm ntawm cov ceev molecular hauv cov roj. Maxwell qhov kev faib tawm ntawm cov ceev molecular tau los ntawm kev tshawb fawb kinetic, thiab yog li ntawd nws yog qhov tseeb dua rau cov roj zoo tagnrho. Maxwell qhov kev faib tawm ntawm cov ceev molecular tshwm sim raws li pom hauv daim duab hauv qab no.
Xyoo 1920, ntau tus kws tshawb fawb tau ua kev sim los tshawb nrhiav qhov ceev ntawm cov roj molecule tiag tiag. Nws tau qhia tias qhov ceev ntawm cov roj molecule tiag tiag uas pom los ntawm kev sim yog tib yam li Maxwell cov kev tshawb pom.
Thaum qhov ceev ntawm cov pa roj siab txaus, qhov kev faib tawm ceev ntawm cov pa roj tiag tiag tsis phim qhov kev faib tawm ceev theoretical los ntawm Maxwell. Yog li, Maxwell qhov kev faib tawm, raws li kev tshawb fawb kinetic ntawm cov pa roj siv Newtonian mechanics, yog txwv. Qhov kev faib tawm ceev ntawm cov pa roj ntawm qhov ceev siab tuaj yeem piav qhia los ntawm cov hauv paus ntsiab lus quantum.
Qhov kev faib tawm ntawm tus nqi ntawm cov roj molecules tiag tiag tau los ntawm kev sim zoo li daim duab hauv qab no.
Daim duab no qhia txog kev faib tawm ntawm qhov ceev ntawm cov roj molecule tiag tiag rau ob qhov kub sib txawv. Daim duab ntawm kev faib tawm ntawm qhov ceev ntawm cov molecule tau los ntawm qhov kev sim no haum rau v rms equation saum toj no (v rms yog proportional ncaj qha rau qhov kub). Vim tias v rms yog proportional ncaj qha rau qhov kub, thaum qhov kub nce (T2), qhov nkhaus faib tawm ntawm tus nqi molecular txav mus rau sab xis ntxiv (v rms loj dua). EA (lub zog ua kom muaj zog) yog lub zog kinetic tsawg kawg nkaus uas xav tau rau kev tshuaj lom neeg tshwm sim.
Los ntawm daim duab saum toj no, nws zoo li qhov kub siab dua, cov molecule ntau dua muaj lub zog kinetic ntau dua li lub zog ua kom muaj zog (EA). Qhov no yog vim li cas qhov kub siab dua, qhov tshuaj tiv thaiv sai dua. Qhov kub siab dua, lub zog kinetic ntawm cov molecule ntau dua. Vim tias cov molecule muaj lub zog kinetic siab, thaum lawv sib tsoo, lawv tuaj yeem lo ua ke.
Piv txwv lo lus nug 1:
Txheeb xyuas qhov rms v ntawm lub molecule Nitrogen (N2) nyob rau hauv huab cua ntawm qhov kub ntawm 20 oC (Qhov hnyav ntawm cov pa roj nitrogen = 28 grams/mol = 28 kg/kmol)
Kev Sib Tham
k = 1,38 x 1023 J/K = 1,38 x 1023 (kg/m²)2 /s2 )/K
TXL = 20 oC + 273 = 293 K
Molar mass los yog molecular mass N2 (M) = 2 x 14 u = 2 x14 gram/mol = 28 gram/mol = 28 kg/kmol (qhov hnyav ntawm atomic N = 14 u. saib lub rooj teev cov ntsiab lus)
Tus naj npawb ntawm cov molecule/mol = Avogadro's Number (NA) = 6,02 x 1023 /mol = 6,02 x 1026 /kmol
Qhov hnyav ntawm Nitrogen (m) = ?
Tus nqi ntawm cov pa roj nitrogen (v rms) = ?
Piv txwv lo lus nug 2:
Txheeb xyuas qhov vrms ntawm Helium (He) hauv huab cua ntawm qhov kub ntawm 20 oC…. (Qhov hnyav molecular ntawm Helium = 4 grams/mol = 4 kg/kmol)
Kev Sib Tham
k = 1,38 x 1023 J/K
TXL = 20 oC + 273 = 293 K
Molar mass/Molecular mass ntawm He (M) = 4 u = 4 gram/mol = 4 kg/kmol (atomic mass ntawm He = 4 u. saib lub rooj periodic ntawm cov ntsiab lus)
Tus naj npawb ntawm cov molecule/mol = Avogadro's Number (NA) = 6,02 x 1023 /mol = 6,02 x 1026 /kmol
Qhov hnyav He (m) = ?
RMS tus nqi He (v rms) = ?
Piv txwv lo lus nug 3:
Txheeb xyuas qhov rms v ntawm Hydrogen (H2) nyob rau hauv huab cua ntawm qhov kub ntawm 20 oC…. (Hydrogen molecular mass = 2 grams/mol = 4 kg/kmol)
Kev Sib Tham
k = 1,38 x 1023 J/K
TXL = 20 oC + 273 = 293 K
Molar mass/M molecular mass ntawm Hydrogen (M) = 2 x 1 u = 2 u = 2 grams/mol = 2 kg/kmol (atomic mass ntawm H = 1 u. saib periodic table of elements)
Tus naj npawb ntawm cov molecule/mol = Avogadro's Number (NA) = 6,02 x 1023 /mol = 6,02 x 1026 /kmol
Pawg H2 (m) = ?
RMS tus nqi H2 (v rms) = ?
Piv txwv lo lus nug 4:
Txheeb xyuas tus nqi rms ntawm cov pa oxygen molecular (O2) nyob rau hauv huab cua ntawm qhov kub ntawm 20 oC. (qhov hnyav ntawm O2 = 32 grams/mol = 44 kg/kmol)
Kev Sib Tham
k = 1,38 x 10 23 J/K
TXL = 20 oC + 273 = 293 K
Molar mass/Molecular mass ntawm Oxygen (M) = 2 x 16 u = 32 u = 32 gram/mol = 32 kg/kmol (atomic mass O = 16 u. saib lub rooj periodic ntawm cov ntsiab lus)
Tus naj npawb ntawm cov molecule/mol = Avogadro's Number (NA) = 6,02 x 1023 /mol = 6,02 x 1026 /kmol
Pawg O2 (m) = ?
RMS tus nqi H2 (v rms) = ?
Piv txwv lo lus nug 5:
Txheeb xyuas tus nqi rms ntawm cov pa roj carbon dioxide (CO) molecules.2) nyob rau hauv huab cua ntawm qhov kub ntawm 20 oC. (qhov hnyav ntawm CO2 = 44 grams/mol = 44 kg/kmol)
Kev Sib Tham
k = 1,38 x 1023 J/K = 1,38 x 1023 (kg/m²)2 /s2 )/K
TXL = 30 oC + 273 = 293 K
Molar mass/Molecular mass ntawm CO2 (M) = 12 u + (2 x 16 u) = 12 u + 32 u = 44 u = 44 gram/mol = 44 kg/kmol (qhov hnyav ntawm C = 12 u, qhov hnyav ntawm O = 16 u. Saib daim ntawv teev cov ntsiab lus)
Tus naj npawb ntawm cov molecule / mol = Avogadro tus lej (N)A) = 6,02 x 1023 /mol = 6,02 x 1026 /kmol
Qhov hnyav ntawm CO2 (m) = ?
Tus nqi CO rms2 (v rms ) = ?
v rms ntawm qee hom roj
Tam sim no cia peb piv cov rms v ntawm ntau hom roj:
v rms Hydrogen (H2) = 1917 m/s = 1,92 km/s (ntawm qhov kub ntawm 20 oC)
v rms Helium (He) = 1355,7 m/s = 1,36 km/s (ntawm qhov kub ntawm 20 oC)
v rms Nitrogen (N2) = 510,75 m/s = 0,51 km/s (ntawm qhov kub ntawm 20 oC)
v rms Cov pa oxygen (O2) = 478,4 m/s = 0,48 km/s (ntawm qhov kub ntawm 20 oC)
v rms carbon dioxide (CO2) = 407,6 m/s = 0,41 km/s (ntawm qhov kub ntawm 20 oC)
Cov roj uas muaj qhov ceev rms siab tshaj plaws yog hydrogen, thiab qhov qis tshaj plaws yog carbon dioxide. Tam sim no piv qhov no rau qhov ceev tawm ntawm lub ntiaj teb (qhov ceev tawm = 11,2 km/s). Qhov ceev tawm yog qhov ceev tsawg kawg nkaus uas xav tau rau ib yam khoom kom tawm ntawm lub ntiaj teb lub zog gravitational.
Yog tias qhov vrms ntawm cov roj molecule tsuas yog 1/6 npaug ntawm qhov ceev khiav tawm (1/6 x 11,2 km/s = 1,86 km/s), ces muaj ntau cov roj molecule uas qhov ceev ntau dua qhov ceev khiav tawm (nco ntsoov qhov kev faib tawm ntawm qhov ceev molecular piav qhia saum toj no). Ntawm qhov kub ntawm 20 oC, v rms ntawm Hydrogen roj = 1,92 km/s (> 1,86 km/s). Thaum v rms ntawm helium roj ntawm qhov kub ntawm 20 oC = 1,36 km/h (ze li 1,86 km/s). Qhov no yog nyob rau ntawm qhov kub ntawm 20 oC.
Qhov kub siab dua, qhov nqi rms siab dua. Qhov nqi rms siab dua, qhov muaj feem ntau dua ntawm kev khiav tawm ntawm lub ntiajteb txawj nqus. Qhov no yog qhov laj thawj vim li cas helium dawb thiab hydrogen tsis muaj nyob rau hauv lub ntiajteb huab cua.
Qhov loj ntawm lub ntiaj teb qhov ceev khiav tawm thiab qhov ceev rms ntawm cov pa roj txiav txim siab hom huab cua uas lub ntiaj teb lossis lub satellite muaj. Qhov ceev khiav tawm ntawm lub ntiaj teb Venus = 10,3 km/s. v rms CO2 me me heev uas nws nyuaj rau nws khiav tawm ntawm Venus huab cua. Lub caij no, Jupiter qhov khiav tawm yog 60 km / s, uas yog siab heev vim Jupiter txoj kab uas hla loj. Yog li ntawd, hydrogen thiab helium tsis tuaj yeem khiav tawm ntawm Jupiter lub zog gravitational.
