Qhov sib txawv tseem ceeb ntawm qhov hnyav atomic thiab atomic mass yog qhov hnyav atomic yog qhov hnyav nruab nrab ntawm lub caij, nrog rau tag nrho nws cov isotopes thiab lawv cov txheeb ze abundances tab sis, atomic mass yog qhov loj ntawm ib lub atom.
Cov neeg feem coob siv cov ntsiab lus atomic mass thiab atomic hnyav sib hloov. Txawm li cas los xij, lawv dais lub ntsiab lus sib txawv, thiab nws ua rau muaj qhov yuam kev loj hauv kev suav cov khoom siv ntau yog tias peb siv ob nqe lus no ua ib qho.
Atomic hnyav yog dab tsi?
Atomic hnyav yog qhov hnyav nruab nrab ntawm ib lub caij, nrog rau tag nrho nws cov isotopes thiab lawv cov txheeb ze abundance. Feem ntau, cov khoom siv tshuaj muaj isotopes; isotopes yog cov qauv sib txawv ntawm tib yam tshuaj lom neeg. Isotopes muaj tib tus naj npawb ntawm cov protons (uas ua rau lawv nyob rau tib yam tshuaj lom neeg) thiab cov lej sib txawv ntawm cov neutrons hauv atomic nucleus. Muaj ntau feem pua ntawm cov isotopes sib txawv uas tshwm sim hauv qhov xwm txheej. Peb yuav tsum xav txog cov atomic masses ntawm tag nrho cov isotopes thiab lawv cov feem pua thaum tau txais qhov hnyav atomic ntawm cov khoom siv tshuaj. Nyob ntawd, peb tuaj yeem xam qhov nruab nrab loj siv cov atomic masses ntawm txhua isotope kom tau qhov hnyav atomic. Qhov hnyav atomic uas peb pom nyob rau hauv lub sij hawm yog xam raws li qhov tshwm sim no.
Peb tuaj yeem siv ob kauj ruam hauv qab no rau kev suav no;
- Ua ntej, hloov cov feem pua rau cov lej lej los ntawm kev faib lawv nrog 100.
- Tom ntej no, muab cov atomic masses ntawm txhua isotope los ntawm cov lej lej no raws li.
- Thaum kawg, ntxiv cov lus teb ua ke kom tau cov lus teb kawg.
Video 1: Xam cov Atomic Weight
Piv txwv: Piv txwv tias peb muaj 98% ntawm C-12 isotope thiab 2% ntawm C-13 isotope nyob rau hauv qhov. Cia peb suav cov atomic hnyav ntawm carbon siv cov atomic masses ntawm cov isotopes.
- Kev hloov pauv mus rau tus lej lej:
- Tus nqi qis rau feem pua ntawm C-12 yog 0.98 (tau los ntawm kev faib 98 ntawm 100).
- Tus nqi qis rau feem pua ntawm C-13 yog 0.02 (tau los ntawm kev faib 2 ntawm 100).
- Ntau qhov ntawm atomic masses ntawm txhua isotope los ntawm tus lej lej:
- 12 x 0.98=11.76
- 13 x 0.02=0.26
- Ntxiv cov lus teb ua ke kom tau cov lus teb kawg:
76 + 0.26=12.02
Thaum kawg, peb tuaj yeem tau txais qhov hnyav atomic ntawm cov tshuaj lom neeg carbon li 12.02 amu (atomic mass units). Tsis tas li ntawd, peb tuaj yeem muab lub npe no ua "tus txheeb ze atomic mass" vim tias nws yog qhov nruab nrab ntawm qhov tseeb atomic masses ntawm isotopes.
Atomic Mass yog dab tsi?
Atoms feem ntau muaj cov protons, neutrons thiab electrons. Atomic mass tsuas yog qhov loj ntawm lub atom. Nyob rau hauv lwm yam lus, nws yog sau los ntawm masses ntawm tag nrho cov neutrons, protons thiab electrons nyob rau hauv ib tug tib atom, tshwj xeeb tshaj yog, thaum lub atom tsis txav (so mass). Peb tsuas yog siv cov khoom seem xwb vim hais tias raws li cov hauv paus ntsiab lus ntawm physics thaum atoms txav ntawm qhov nrawm heev cov huab hwm coj nce. Txawm li cas los xij, qhov loj ntawm electrons yog qhov tsawg heev piv rau qhov loj ntawm protons thiab neutrons. Yog li ntawd, peb tuaj yeem hais tias cov khoom siv hluav taws xob rau cov khoom siv atomic tsawg dua. Yog li peb tuaj yeem tsis quav ntsej qhov loj ntawm ib qho hluav taws xob thaum xam cov atomic mass. Qhov tseem ceeb tshaj, cov isotopes sib txawv muaj qhov sib txawv atomic masses txawm hais tias lawv nyob rau tib yam tshuaj lom neeg vim lawv muaj cov lej sib txawv ntawm neutrons.
Daim duab 01: Peb tuaj yeem siv cov huab hwm coj ntawm protons, neutrons thiab electrons ntawm lub atom los xam cov Atomic Mass
Ntxiv mus, qhov loj ntawm cov atoms tsawg heev, yog li peb tsis tuaj yeem qhia lawv hauv ib qho loj xws li grams lossis kilograms. Rau peb lub hom phiaj, peb tab tom siv lwm chav hu atomic mass unit (amu) los ntsuas atomic mass. Ib yam li ntawd, 1 atomic mass unit yog ib feem kaum ntawm qhov loj ntawm C-12 isotope. Thaum peb faib ib pawg ntawm ib qho atom los ntawm qhov loj ntawm ib feem kaum ntawm qhov loj ntawm C-12 isotope, peb tuaj yeem tau txais nws cov txheeb ze. Txawm li cas los xij, hauv kev siv dav dav thaum peb hais qhov txheeb ze atomic loj ntawm lub caij, peb txhais tau tias lawv qhov hnyav atomic (vim peb suav nws suav nrog tag nrho cov isotopes).
Qhov txawv ntawm Atomic Weight thiab Atomic Mass yog dab tsi?
Feem ntau peb siv cov ntsiab lus atomic hnyav thiab atomic mass tib yam. Txawm li cas los xij, ob nqe lus no txawv ntawm ib leeg los ntawm kev txhais. Yog li ntawd, mus los ntawm lub ntsiab lus, qhov sib txawv tseem ceeb ntawm qhov hnyav ntawm atomic thiab atomic mass yog qhov hnyav atomic yog qhov hnyav nruab nrab ntawm ib lub caij, nrog rau tag nrho nws cov isotopes thiab lawv cov txheeb ze abundances whereas lub atomic mass yog qhov loj ntawm ib atom..
Tsis tas li ntawd, peb tuaj yeem txheeb xyuas qhov sib txawv tseem ceeb ntawm qhov hnyav ntawm atomic thiab atomic mass los ntawm kev txiav txim siab txog kev suav txhua tus nqi; Peb yuav tsum xam cov atomic hnyav uas siv cov feem pua ntawm tag nrho cov isotopes ntawm ib tug tshuaj nyob rau hauv cov xwm thaum peb yuav xam cov atomic loj los ntawm kev ntxiv cov masses ntawm protons, neutrons thiab electrons ntawm ib atom.
Summary – Atomic Weight vs Atomic Mass
Atomic hnyav thiab atomic mass yog ob lo lus tseem ceeb uas peb feem ntau siv hauv kev suav tshuaj. Qhov sib txawv tseem ceeb ntawm qhov hnyav atomic thiab atomic mass yog qhov hnyav atomic yog qhov hnyav nruab nrab ntawm ib lub caij, nrog rau tag nrho nws cov isotopes thiab lawv cov txheeb ze abundances whereas atomic mass yog qhov loj ntawm ib atom.
