Cov khoom siv ceev thiab lub ntiajteb txawj nqus tshwj xeeb
Qhov Ceev
Ib qho ntawm cov yam ntxwv tseem ceeb ntawm ib yam khoom yog qhov ceev. Qhov ceev yog qhov sib piv ntawm qhov hnyav ntawm ib yam khoom rau nws qhov ntim. Hauv lej, nws yog sau li:
ρ = m/V
ρ yog tsab ntawv Greek uas feem ntau siv los qhia txog qhov ceev, m sawv cev rau pawg, thiab V sawv cev rau ntim. Qhov ceev ntawm cov kua dej sib xyaw yog qhov sib txawv ntawm qhov ceev ntawm cov khoom sib xyaw. Hlau lossis dej khov, piv txwv li, muaj qhov ceev tib yam hauv txhua qhov. Qhov no txawv ntawm cov kua dej, xws li huab cua lossis dej. Hauv lub ntiaj teb huab cua, qhov siab dua ntawm huab cua ntawm lub ntiaj teb nto, qhov ceev qis dua, thaum rau dej hiav txwv, piv txwv li, qhov tob dua qhov ceev, qhov ceev ntau dua. Qhov ceev ntawm cov kua dej sib xyaw tuaj yeem nyob ntawm cov yam ntxwv ib puag ncig xws li kub thiab siab.
Lub Txheej Txheem Thoob Ntiaj Teb ntawm Chav rau qhov ceev yog kilograms ib cubic meter (kg/m3 ) . Rau CGS units, uas yog centimeters, grams, thiab vib nas this, qhov ceev yog qhia hauv grams ib cubic centimeter (gr/cm3 ) . Cov hauv qab no yog cov ntaub ntawv ceev rau ntau yam khoom.
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Tus Neeg
Qhov Ceev (kg/ m3 )
Kua
Cua
Dej hiav txwv
Ntshav
Roj av
Mercury
1,00 x 10 3
1,03 x 10 3
1,06 x 10 3
0,68 x 10 3
13,6 x 10 3
Khoom khov kho
Es
txhuas
Hlau
Emas
Iav
Ntoo
Tembag
Timah
Tulang
0,92 x 10 3
2,70 x 10 3
7,8 x 10 3
19,3 x 10 3
2,4 – 2,8 x 10 3
0,3 – 0,9 x 10 3
8,9 x 10 3
11,3 x 10 3
1,7 – 2.0 x 10 3
Cov Khoom Siv Gases
Udara
Helium
Hydrogen
Cov pa dej (100 o C)
1,293
0,1786
0,08994
0,6
Qhov ceev ntawm cov khoom uas tau hais nyob rau hauv lub rooj saum toj no yog qhov ceev ntawm cov khoom ntawm qhov kub ntawm 0 o C thiab qhov siab ntawm 1 atm (atm = unit of pressure).
Lub zog nqus tshwj xeeb
Qhov hnyav tshwj xeeb yog qhov sib piv ntawm qhov ceev ntawm ib yam khoom rau qhov ceev ntawm dej. Qhov hnyav tshwj xeeb ntawm ib yam khoom tuaj yeem tau los ntawm kev faib nws qhov ceev los ntawm 103 kg / m3 ( qhov ceev ntawm dej). Qhov hnyav tshwj xeeb tsis muaj qhov ntev.
Yog tias qhov ceev ntawm ib yam khoom tsawg dua qhov ceev ntawm dej, ces yam khoom ntawd yuav ntab. Qhov hnyav tshwj xeeb ntawm ib yam khoom ntab yog tsawg dua 1. Ntawm qhov tod tes, yog tias qhov ceev ntawm ib yam khoom ntau dua qhov ceev ntawm dej, ces nws qhov hnyav tshwj xeeb yog ntau dua 1. Hauv qhov no, yam khoom ntawd yuav tog.
