Rau lub sijhawm ntev, cov kws tshawb fawb tau sim tsim cov kev tshawb fawb sib koom ua ke uas yuav piav qhia cov qauv ntawm cov molecules, piav qhia lawv cov khoom muaj feem cuam tshuam nrog lwm yam khoom. Ua li no, lawv yuav tsum piav qhia txog qhov xwm txheej thiab cov qauv ntawm lub atom, qhia cov ntsiab lus ntawm "valency", "electron density" thiab ntau lwm tus.
keeb kwm ntawm kev tsim txoj kev xav
Cov qauv tshuaj ntawm cov tshuaj thawj zaug nyiam Italian Amadeus Avogadro. Nws pib kawm txog qhov hnyav ntawm cov molecules ntawm ntau yam gases thiab, raws li nws cov kev soj ntsuam, muab tso rau pem hauv ntej ib tug hypothesis txog lawv cov qauv. Tab sis nws tsis yog thawj tus tshaj tawm rau nws, tab sis tos kom txog thaum nws cov npoj yaig tau txais cov txiaj ntsig zoo sib xws. Tom qab ntawd, txoj hauv kev kom tau txais qhov hnyav molecular ntawm cov pa roj tau hu ua Avogadro Txoj Cai.
Txoj kev xav tshiab tau ua rau lwm tus kws tshawb fawb los kawm. Ntawm lawv yog Lomonosov, D alton, Lavoisier, Proust, Mendeleev thiab Butlerov.
Butlerov's theory
Lo lus "kev xav ntawm cov qauv tshuaj" thawj zaug tau tshwm sim hauv tsab ntawv tshaj tawm txog cov qauv ntawm cov khoom, uas Butlerov nthuav tawm hauv Tebchaws Yelemees xyoo 1861. Nws tau suav nrog yam tsis muaj kev hloov pauv hauv cov ntawv tshaj tawm tom ntej thiabentrenched nyob rau hauv lub annals ntawm keeb kwm ntawm science. Qhov no yog tus thawj coj ntawm ntau qhov kev xav tshiab. Hauv nws cov ntaub ntawv, tus kws tshawb fawb tau piav qhia nws tus kheej saib ntawm cov qauv tshuaj ntawm cov tshuaj. Nov yog qee qhov ntawm nws cov no:
- atoms nyob rau hauv molecules txuas rau ib leeg raws li tus naj npawb ntawm electrons nyob rau hauv lawv cov orbitals txheej;
- kev hloov nyob rau hauv ib theem ntawm kev sib txuas ntawm atoms ua rau ib tug hloov nyob rau hauv lub zog ntawm lub molecule. thiab cov tsos ntawm ib yam khoom tshiab;
- tshuaj thiab lub cev lub zog ntawm cov tshuaj nyob ntawm seb tsis yog ntawm cov atoms suav nrog hauv nws cov khoom, tab sis kuj nyob ntawm qhov kev txiav txim ntawm lawv txoj kev sib txuas rau ib leeg, nrog rau kev sib koom tes.;- txhawm rau txiav txim siab cov molecular thiab atomic muaj pes tsawg leeg ntawm cov khoom, nws yog ib qho tsim nyog los kos cov saw ntawm kev hloov pauv mus ua tiav.
Geometric qauv ntawm molecules
Cov qauv tshuaj ntawm atom thiab molecules tau ntxiv peb xyoos tom qab los ntawm Butlerov nws tus kheej. Nws qhia txog qhov tshwm sim ntawm isomerism rau hauv kev tshawb fawb, postulating tias, txawm tias muaj qhov zoo sib xws, tab sis cov qauv sib txawv, cov tshuaj yuav txawv ntawm ib leeg hauv ntau qhov ntsuas.
Kaum xyoo tom qab, cov lus qhuab qhia ntawm cov qauv peb sab ntawm cov molecules tshwm. Nws tag nrho pib nrog kev tshaj tawm los ntawm van't Hoff ntawm nws txoj kev xav ntawm quaternary system ntawm valences hauv carbon atom. Cov kws tshawb fawb niaj hnub paub qhov txawv ntawm ob thaj chaw ntawm stereochemistry: cov qauv thiab spatial.
Nyob rau hauv lem, cov txheej txheem ib feem kuj muab faib ua isomerism ntawm lub cev pob txha thiab txoj hauj lwm. Qhov no yog ib qho tseem ceeb uas yuav tsum tau coj mus rau hauv tus account thaum kawm cov khoom siv organic, thaum lawv cov khoom muaj txiaj ntsig zoo li qub, thiab tsuas yogtus naj npawb ntawm hydrogen thiab carbon atoms thiab qhov sib lawv liag ntawm lawv cov tebchaw nyob rau hauv lub molecule.
Spatial isomerism yog qhov tsim nyog thaum muaj cov tebchaw uas nws cov atoms tau teeb tsa tib yam, tab sis hauv qhov chaw cov molecule nyob txawv. Muab faib kho qhov muag isomerism (thaum stereoisomers tsom ib leeg), diasteriomerism, geometric isomerism thiab lwm yam.
Atoms hauv molecules
Cov qauv tshuaj classical ntawm ib lub molecule txhais tau tias muaj ib qho atom hauv nws. Hypothetically, nws yog tseeb hais tias lub atom nws tus kheej nyob rau hauv ib tug molecule yuav hloov, thiab nws cov khoom kuj hloov tau. Nws nyob ntawm seb lwm cov atoms nyob ib puag ncig nws, qhov kev ncua deb ntawm lawv thiab cov ntawv cog lus uas muab lub zog ntawm cov molecule.
Cov kws tshawb fawb niaj hnub no, xav kom rov sib haum xeeb txoj kev xav ntawm kev sib raug zoo thiab quantum txoj kev xav, lees txais qhov chaw pib qhov tseeb tias thaum lub molecule raug tsim, lub atom tsuas tshuav ib lub nucleus thiab electrons rau nws, thiab nws tus kheej tsis muaj nyob.. Ntawm chav kawm, qhov formulation no tsis tau mus txog tam sim ntawd. Ntau qhov kev sim tau ua los khaws lub atom ua ib chav tsev ntawm cov molecule, tab sis lawv txhua tus ua tsis tau raws li lub siab xav.
qauv, tshuaj muaj pes tsawg leeg ntawm tes
Lub tswv yim ntawm "kev sib xyaw" txhais tau tias kev sib koom ua ke ntawm txhua yam khoom uas koom nrog hauv kev tsim thiab lub neej ntawm tes. Cov npe no suav nrog yuav luag tag nrho cov lus ntawm lub caij nyoog:
- yim caum-rau lub ntsiab lus ib txwm muaj;
- nees nkaum tsib ntawm lawv yog kev txiav txim siab rau ib txwmlub neej;- txog nees nkaum ntxiv yog qhov tsim nyog.
tsib tus yeej yog qhib los ntawm oxygen, cov ntsiab lus ntawm cov cell mus txog xya caum-tsib feem pua hauv txhua lub xov tooj. Nws yog tsim thaum lub sij hawm decomposition ntawm dej, yog tsim nyog rau cellular respiration tshwm sim thiab muab lub zog rau lwm yam tshuaj. Tom ntej no hauv qhov tseem ceeb yog carbon. Nws yog lub hauv paus ntawm tag nrho cov organic tshuaj, thiab kuj yog ib tug substrate rau photosynthesis. Bronze tau txais hydrogen - feem ntau cov khoom nyob rau hauv lub ntug. Nws tseem muaj nyob rau hauv cov organic tebchaw nyob rau tib theem li carbon. Nws yog ib qho tseem ceeb ntawm cov dej. Qhov chaw thib plaub uas muaj txiaj ntsig yog nyob ntawm nitrogen, uas yog qhov tsim nyog rau kev tsim cov amino acids thiab, vim li ntawd, cov proteins, enzymes thiab cov vitamins.
Cov qauv tshuaj ntawm tes kuj suav nrog cov ntsiab lus tsis tshua muaj xws li calcium, phosphorus, potassium, sulfur, chlorine, sodium thiab magnesium. Ua ke lawv tuav txog ib feem pua ntawm tag nrho cov teeb meem hauv lub cell. Microelements thiab ultramicroelements tseem raug cais tawm, uas pom muaj nyob hauv cov kab mob muaj sia nyob hauv cov lej.
