Los ntawm lub sijhawm qub txeeg qub teg mus rau nruab nrab ntawm lub xyoo pua 18th, kev tshawb fawb tau ua tiav los ntawm lub tswv yim tias atom yog ib feem ntawm cov teeb meem uas tsis tuaj yeem faib. Tus kws tshawb fawb Askiv, nrog rau tus kws paub txog ntuj tsim D. D alton, txhais lub atom yog qhov tsawg tshaj plaws ntawm cov khoom siv tshuaj. M. V. Lomonosov nyob rau hauv nws atomic thiab molecular txoj kev xav tau txhais lub atom thiab lub molecule. Nws ntseeg tau tias cov molecules, uas nws hu ua "corpuscles", tau ua los ntawm "cov ntsiab lus" - atoms - thiab nyob rau hauv tas li motion.
D. I. Mendeleev ntseeg hais tias qhov subunit ntawm cov khoom uas tsim cov khoom ntiaj teb khaws tag nrho nws cov khoom tsuas yog tias nws tsis raug cais tawm. Hauv kab lus no, peb yuav txhais lub atom ua ib yam khoom ntawm microworld thiab kawm nws cov khoom.
Yam yuav tsum tau ua ua ntej rau kev tsim txoj kev xav ntawm cov qauv ntawm lub atom
Nyob rau xyoo pua 19th, cov lus hais txog qhov tsis pom kev ntawm lub atom feem ntau tau txais. Cov kws tshawb fawb feem ntau ntseeg tias cov khoom ntawm ib qho tshuaj lom neeg tsis muaj xwm txheej tuaj yeem hloov mus rau hauv atoms ntawm lwm lub caij. Cov tswv yim no tau ua raws li lub hauv paus uas lub ntsiab lus ntawm lub atom yog nyob rau hauv 1932. Thaum kawg ntawm lub xyoo pua puv 19, science tau tsimCov kev tshawb pom tseem ceeb uas hloov qhov kev xav no. Ua ntej ntawm tag nrho cov, nyob rau hauv 1897, cov lus Askiv physicist J. J. Thomson nrhiav tau lub electron. Qhov tseeb no tau hloov pauv cov tswv yim ntawm cov kws tshawb fawb txog qhov tsis sib xws ntawm cov khoom siv ntawm cov tshuaj lom neeg.
Yuav ua li cas ua pov thawj tias lub atom yog complex
Txawm tias ua ntej kev tshawb pom ntawm electron, cov kws tshawb fawb tau pom zoo tias cov atoms tsis muaj nqi. Tom qab ntawd nws tau pom tias cov hluav taws xob tau yooj yim tso tawm los ntawm cov khoom siv tshuaj lom neeg. Lawv tuaj yeem pom hauv nplaim taws, lawv yog cov nqa hluav taws xob tam sim no, lawv raug tso tawm los ntawm cov khoom thaum lub sij hawm X-ray emission.
Tab sis yog tias electrons yog ib feem ntawm tag nrho cov atoms yam tsis muaj kev zam thiab raug them tsis zoo, ces muaj qee qhov lwm yam hauv atom uas yuav tsum muaj tus nqi zoo, txwv tsis pub cov atoms yuav tsis muaj hluav taws xob nruab nrab. Txhawm rau pab tshem tawm cov qauv ntawm lub atom, xws li lub cev tshwm sim raws li kev siv hluav taws xob tau pab. Nws muab qhov tseeb txhais ntawm lub atom hauv physics thiab tom qab ntawd hauv chemistry.
Tsis pom rays
Fab Kis tus kws kho mob A. Becquerel yog thawj tus piav qhia txog qhov tshwm sim ntawm emission los ntawm atoms ntawm qee yam tshuaj lom neeg, pom qhov tsis pom kev. Lawv ionize huab cua, dhau los ntawm cov khoom, ua rau blackening ntawm daim duab duab. Tom qab ntawd, Curies thiab E. Rutherford pom tias cov tshuaj radioactive tau hloov mus rau hauv atoms ntawm lwm cov tshuaj (piv txwv li, uranium rau hauv neptunium).
Radioactive hluav taws xob yog inhomogeneous nyob rau hauv muaj pes tsawg leeg: alpha hais, beta hais, gamma rays. Yog liYog li, qhov tshwm sim ntawm radioactivity tau lees paub tias cov khoom ntawm cov ntsiab lus ntawm lub rooj zaum muaj cov qauv tsim. Qhov tseeb no yog vim li cas rau kev hloov pauv rau lub ntsiab lus ntawm lub atom. Dab tsi yog ib qho atom muaj xws li, muab qhov tseeb tshiab tshawb fawb tau los ntawm Rutherford? Cov lus teb rau lo lus nug no yog tus qauv nuclear ntawm lub atom tau thov los ntawm tus kws tshawb fawb, raws li cov khoom siv hluav taws xob hloov pauv nyob ib puag ncig lub nucleus uas muaj txiaj ntsig zoo.
Kev tsis sib haum xeeb ntawm tus qauv Rutherford
Txoj kev xav ntawm tus kws tshawb fawb, txawm tias nws tus cwj pwm zoo, tsis tuaj yeem txhais lub atom. Nws cov lus xaus tau tawm tsam cov kev cai tseem ceeb ntawm thermodynamics, raws li qhov uas txhua tus electrons revolving nyob ib ncig ntawm lub nucleus poob lawv lub zog thiab, raws li nws tej zaum yuav, sai los yog tom qab yuav tsum tau poob rau hauv nws. Lub atom puas lawm nyob rau hauv cov ntaub ntawv no. Qhov no tsis tshwm sim tiag tiag, txij li cov khoom siv tshuaj thiab cov khoom uas lawv tau tsim muaj nyob hauv qhov xwm txheej ntev heev. Xws li lub ntsiab lus ntawm lub atom, raws li Rutherford txoj kev xav, yog qhov tsis txaus ntseeg, nrog rau qhov tshwm sim uas tshwm sim thaum cov khoom kub kub tau dhau los ntawm qhov sib txawv ntawm grating. Tom qab tag nrho, lub resulting atomic spectra muaj ib tug linear duab. Qhov no yog qhov tsis sib haum xeeb nrog Rutherford tus qauv ntawm lub atom, raws li qhov spectra yuav tsum tau ua tas mus li. Raws li cov ntsiab lus ntawm quantum mechanics, tam sim no, electrons hauv lub nucleus tsis yog cov khoom taw tes, tab sis raws li muaj daim ntawv ntawm huab cua electron.
Nws qhov ceev tshaj plaws nyob rau hauv ib qho chaw ntawm qhov chaw nyob ib ncig ntawm lub nucleus thiabsuav tias yog qhov chaw ntawm qhov particle ntawm ib qho chaw hauv lub sijhawm. Nws kuj tau pom tias cov electrons nyob rau hauv lub atom yog teem nyob rau hauv txheej. Tus naj npawb ntawm cov khaubncaws sab nraud povtseg tuaj yeem txiav txim siab los ntawm kev paub txog cov naj npawb ntawm lub sijhawm uas lub caij nyob rau hauv lub sijhawm ntawm D. I. Mendeleev. Piv txwv li, phosphorus atom muaj 15 electrons thiab muaj 3 qib zog. Qhov taw qhia uas txiav txim siab tus lej ntawm lub zog yog hu ua tus lej quantum tseem ceeb.
Nws tau sim pom tias cov electrons ntawm lub zog theem ze tshaj plaws ntawm lub nucleus muaj lub zog qis tshaj. Txhua lub plhaub lub zog tau muab faib ua sublevels, thiab lawv, dhau los, mus rau hauv orbitals. Electrons nyob rau hauv txawv orbitals muaj tib lub huab zoo (s, p, d, f).
Raws li cov saum toj no, nws ua raws li cov duab ntawm cov huab cua hluav taws xob tsis tuaj yeem raug txiav txim siab. Nws yog nruj me ntsis txhais raws li lub orbital quantum tooj. Peb kuj ntxiv hais tias lub xeev ntawm ib tug electron nyob rau hauv ib tug macroparticle yog txiav txim los ntawm ob tug ntxiv qhov tseem ceeb - sib nqus thiab spin quantum tooj. Thawj yog raws li Schrödinger sib npaug thiab ua tus yam ntxwv ntawm qhov chaw ncig ntawm lub tshuab hluav taws xob raws li peb-dimensionality ntawm peb lub ntiaj teb. Qhov taw qhia thib ob yog tus lej spin, nws yog siv los txiav txim qhov kev sib hloov ntawm ib qho hluav taws xob nyob ib ncig ntawm nws axis clockwise los yog counterclockwise.
Discovery of the neutron
Ua tsaug rau txoj haujlwm ntawm D. Chadwick, ua los ntawm nws hauv 1932, tau muab lub ntsiab lus tshiab ntawm atom hauv chemistry thiab physics. Hauv nws qhov kev sim, tus kws tshawb fawb tau ua pov thawj tias thaum lub sij hawm tawg ntawm polonium, hluav taws xob tshwm sim, tshwm sim los ntawmcov particles uas tsis muaj nqi, nrog ib tug loj ntawm 1.008665. Tus tshiab elementary particle hu ua lub neutron. Nws nrhiav pom thiab kawm txog nws cov khoom tau tso cai rau cov kws tshawb fawb Soviet V. Gapon thiab D. Ivanenko los tsim ib txoj kev xav tshiab ntawm cov qauv ntawm cov atomic nucleus uas muaj protons thiab neutrons.
Raws li txoj kev xav tshiab, lub ntsiab lus ntawm ib qho atom ntawm cov teeb meem yog raws li nram no: nws yog ib tug structural unit ntawm ib tug tshuaj, uas muaj xws li ib tug nucleus uas muaj protons thiab neutrons thiab electrons tsiv mus nyob ib ncig ntawm nws. Tus naj npawb ntawm cov khoom zoo hauv lub nucleus yeej ib txwm sib npaug rau tus lej atomic ntawm cov tshuaj hauv lub sijhawm.
Tom qab ntawd, Xib Fwb A. Zhdanov tau lees paub hauv nws qhov kev sim uas nyob rau hauv lub zog ntawm lub zog cosmic hluav taws xob, atomic nuclei faib ua protons thiab neutrons. Tsis tas li ntawd, nws tau ua pov thawj tias cov rog tuav cov ntsiab lus tseem ceeb hauv cov nucleus muaj zog heev. Lawv ua haujlwm ntawm qhov deb heev (li 10 -23cm) thiab hu ua nuclear. Raws li tau hais ua ntej, txawm tias M. V. Lomonosov muaj peev xwm muab lub ntsiab lus ntawm lub atom thiab lub molecule raws li qhov tseeb ntawm kev tshawb fawb paub rau nws.
Tam sim no, cov qauv hauv qab no feem ntau lees paub: ib lub atom muaj cov nucleus thiab cov hluav taws xob txav ib ncig ntawm nws raws cov kev txwv nruj heev - orbitals. Electrons ib txhij nthuav tawm cov khoom ntawm ob qho tib si thiab cov nthwv dej, uas yog, lawv muaj ob qhov xwm txheej. Yuav luag tag nrho nws cov loj yog concentrated nyob rau hauv lub nucleus ntawm ib tug atom. Nws yog tsim los ntawm protons thiab neutrons khi los ntawm nuclear rog.
Atom tuaj yeem hnyav
Nws hloov tawm tias txhua lub atom muajpawg. Piv txwv li, rau hydrogen nws yog 1.67x10-24g. Nws tseem nyuaj rau xav txog qhov me me npaum li cas no. Txhawm rau nrhiav qhov hnyav ntawm cov khoom no, lawv tsis siv cov nplai, tab sis ib qho oscillator, uas yog carbon nanotube. Txhawm rau xam qhov hnyav ntawm ib qho atom thiab cov molecule, tus nqi yooj yim dua yog qhov txheeb ze. Nws qhia tau hais tias pes tsawg zaus qhov hnyav ntawm ib lub molecule lossis atom ntau dua 1/12 ntawm cov pa roj carbon atom, uas yog 1.66x10-27 kg. Cov txheeb ze atomic masses tau muab rau hauv lub caij nyoog ntawm cov tshuaj lom neeg, thiab lawv tsis muaj units.
Cov kws tshawb fawb tau paub zoo tias cov atomic loj ntawm cov tshuaj lom neeg yog qhov nruab nrab ntawm cov lej ntawm tag nrho nws cov isotopes. Nws hloov tawm hais tias nyob rau hauv qhov xwm txheej, units ntawm ib yam tshuaj muaj peev xwm muaj sib txawv pawg. Nyob rau tib lub sijhawm, cov nqi ntawm cov nuclei ntawm cov qauv zoo li qub.
Cov kws tshawb fawb tau pom tias isotopes txawv ntawm cov neutrons hauv cov nucleus, thiab cov nqi ntawm lawv cov nuclei yog tib yam. Piv txwv li, ib tug chlorine atom nrog ib tug loj ntawm 35 muaj 18 neutrons thiab 17 protons, thiab nrog ib tug loj ntawm 37 - 20 neutrons thiab 17 protons. Muaj ntau yam tshuaj lom neeg yog sib xyaw ntawm isotopes. Piv txwv li, tej yam yooj yim xws li poov tshuaj, argon, oxygen muaj atoms sawv cev rau 3 txawv isotopes.
Defining atomicity
Nws muaj ntau qhov kev txhais. Xav txog dab tsi yog txhais los ntawm lo lus no hauv chemistry. Yog hais tias cov atoms ntawm tej yam tshuaj muaj peev xwm nyob sib cais tsawg kawg yog ib tug luv luv lub sij hawm, tsis siv zog los tsim ib tug complex particle - ib tug molecule, ces lawv hais tias cov tshuaj muaj.atomic qauv. Piv txwv li, ntau theem methane chlorination tshuaj tiv thaiv. Nws yog dav siv nyob rau hauv chemistry ntawm organic synthesis kom tau qhov tseem ceeb tshaj plaws halogen derivatives: dichloromethane, carbon tetrachloride. Nws faib cov chlorine molecules rau hauv cov atoms uas muaj zog heev. Lawv rhuav tshem cov sigma daim ntawv cog lus hauv cov methane molecule, muab cov kev hloov pauv cov tshuaj tiv thaiv.
Ib qho piv txwv ntawm cov txheej txheem tshuaj lom neeg tseem ceeb hauv kev lag luam yog kev siv hydrogen peroxide ua tshuaj tua kab mob thiab tshuaj dawb. Kev txiav txim siab ntawm atomic oxygen, raws li cov khoom ntawm kev puas tsuaj ntawm hydrogen peroxide, tshwm sim ob qho tib si nyob rau hauv cov hlwb (nyob rau hauv qhov kev txiav txim ntawm catalase enzyme) thiab hauv kev kuaj mob. Atomic oxygen yog qhov tsim nyog txiav txim siab los ntawm nws cov khoom muaj zog antioxidant, nrog rau nws lub peev xwm los rhuav tshem cov kab mob: kab mob, fungi thiab lawv cov spores.
How the atomic plhaub ua haujlwm
Peb twb tau pom ua ntej lawm tias chav tsev ntawm cov khoom siv tshuaj muaj cov qauv nyuaj. Electrons tig ib ncig ntawm lub nucleus zoo. Tus yeej Nobel nqi zog Niels Bohr, raws li lub quantum txoj kev xav ntawm lub teeb, tsim nws cov lus qhuab qhia, nyob rau hauv uas cov yam ntxwv thiab lub ntsiab lus ntawm ib tug atom yog raws li nram no: electrons txav nyob ib ncig ntawm lub nucleus xwb raws li tej yam nyob ruaj ruaj trajectories, thaum lawv tsis radiate zog. Bohr cov lus qhuab qhia tau ua pov thawj tias cov khoom ntawm microcosm, uas suav nrog atoms thiab molecules, tsis ua raws li cov cai uas ncaj ncees.rau lub cev loj - cov khoom macrocosmic.
Cov qauv ntawm cov plhaub electron ntawm macroparticles tau kawm hauv kev ua haujlwm ntawm quantum physics los ntawm cov kws tshawb fawb xws li Hund, Pauli, Klechkovsky. Yog li nws tau paub tias cov khoom siv hluav taws xob ua kom muaj kev sib hloov nyob ib ncig ntawm lub nucleus tsis yog randomly, tab sis raws li qee qhov chaw nyob ruaj khov. Pauli pom tias nyob rau hauv ib theem ntawm lub zog ntawm txhua qhov ntawm nws cov s, p, d, f orbitals, tsis pub ntau tshaj ob qhov tsis zoo nqi nrog cov lus sib txawv + ½ thiab - ½ tuaj yeem pom hauv cov hluav taws xob hluav taws xob.
Hund txoj cai tau piav qhia yuav ua li cas orbitals nrog tib lub zog qib tau raug sau nrog electrons.
Klechkovsky txoj cai, tseem hu ua n + l txoj cai, piav qhia yuav ua li cas lub orbitals ntawm multielectron atoms (cov ntsiab lus ntawm 5, 6, 7 lub sijhawm) tau sau. Tag nrho cov qauv saum toj no tau txais kev lees paub theoretical rau cov txheej txheem ntawm cov tshuaj tsim los ntawm Dmitry Mendeleev.
Oxidation xeev
Nws yog ib lub tswv yim tseem ceeb hauv chemistry thiab qhia txog lub xeev ntawm ib qho atom hauv molecule. Lub ntsiab txhais niaj hnub no ntawm oxidation lub xeev ntawm atoms yog raws li nram no: qhov no yog lub conditional nqi ntawm ib tug atom nyob rau hauv ib lub molecule, uas yog xam raws li kev xav tias lub molecule tsuas muaj ib tug ionic muaj pes tsawg leeg.
Qib ntawm oxidation tuaj yeem qhia tau tias yog tus lej lossis feem ntau, nrog rau qhov zoo, tsis zoo lossis xoom qhov tseem ceeb. Feem ntau, cov tshuaj atoms ntawm cov tshuaj muaj ntau lub xeev oxidation. Piv txwv li, nitrogen muaj -3, -2, 0, +1, +2, +3, +4, +5. Tab sis xws li cov tshuaj lom neeg xws li fluorine, nyob rau hauv tag nrho nwsCov tebchaw tsuas muaj ib lub xeev oxidation, sib npaug rau -1. Yog hais tias nws yog sawv cev los ntawm ib yam khoom yooj yim, ces nws lub xeev oxidation yog xoom. Cov tshuaj muaj pes tsawg leeg no yooj yim siv rau kev faib cov tshuaj thiab piav qhia lawv cov khoom. Feem ntau, lub xeev oxidation ntawm ib lub atom yog siv nyob rau hauv chemistry thaum compiling equations rau redox tshua.
Properties of atoms
Ua tsaug rau qhov kev tshawb pom ntawm quantum physics, lub ntsiab lus niaj hnub ntawm lub atom, raws li txoj kev xav ntawm D. Ivanenko thiab E. Gapon, yog ntxiv los ntawm cov lus tseeb hauv qab no. Cov qauv ntawm cov nucleus ntawm ib lub atom tsis hloov thaum muaj tshuaj lom neeg. Tsuas yog nyob ruaj ruaj electron orbitals yuav raug hloov. Lawv cov qauv tuaj yeem piav qhia ntau yam ntawm lub cev thiab tshuaj lom neeg ntawm cov khoom. Yog hais tias ib qho hluav taws xob tawm ntawm qhov chaw nyob ruaj khov thiab mus rau lub orbit nrog lub zog siab dua, xws li atom hu ua zoo siab.
Nws yuav tsum tau muab sau tseg tias cov hluav taws xob tsis tuaj yeem nyob hauv qhov txawv txav txawv txav mus ntev. Rov qab mus rau nws qhov chaw nyob ruaj khov, lub electron emits ib quantum ntawm lub zog. Kev kawm txog cov yam ntxwv ntawm cov qauv ntawm cov khoom siv tshuaj xws li electron affinity, electronegativity, ionization zog, tso cai rau cov kws tshawb fawb tsis tsuas yog txhais cov atom ua qhov tseem ceeb tshaj plaws ntawm microcosm, tab sis kuj tso cai rau lawv piav qhia txog lub peev xwm ntawm atoms tsim. Qhov ruaj khov thiab nquag muaj zog dua molecular lub xeev ntawm cov teeb meem, ua tau vim yog kev tsim ntau hom tshuaj ruaj khov: ionic, covalentpolar thiab non-polar, pub-acceptor (raws li ib yam ntawm covalent daim ntawv cog lus) thiab nws yog xim hlau. Qhov kawg txiav txim siab qhov tseem ceeb tshaj plaws ntawm lub cev thiab tshuaj lom neeg ntawm tag nrho cov hlau.
Nws tau raug sim tsim kom muaj qhov loj ntawm lub atom hloov tau. Txhua yam yuav nyob ntawm seb qhov twg molecule nws suav nrog. Ua tsaug rau X-ray diffraction tsom xam, nws muaj peev xwm xam qhov kev ncua deb ntawm atoms nyob rau hauv ib tug chemical compound, raws li zoo raws li nrhiav tau tawm lub vojvoog ntawm lub structural unit. Paub txog cov qauv ntawm kev hloov pauv ntawm lub radii ntawm atoms nyob rau hauv ib lub sij hawm los yog pab pawg neeg ntawm cov tshuaj, nws muaj peev xwm kwv yees lawv lub cev thiab tshuaj. Piv txwv li, nyob rau lub sijhawm nrog kev nce nqi ntawm cov nucleus ntawm atoms, lawv cov radii txo qis ("compression of the atom"), yog li cov khoom siv hlau ntawm cov tebchaw tsis muaj zog, thiab cov hlau tsis yog hlau nce.
Yog li, kev paub txog cov qauv ntawm lub atom tso cai rau peb kom raug txiav txim siab lub cev thiab tshuaj lom neeg ntawm txhua lub ntsiab lus suav nrog hauv ntu ntu ntawm Mendeleev.
