Kev txiav txim ntawm atoms thiab molecules. Lus Txhais ntawm ib tug atom kom txog rau thaum 1932

Pib los ntawm lub ancient lub sij hawm mus rau nruab nrab ntawm lub 18th xyoo pua, science twb yeej los ntawm lub xav hais tias atom - ib tug particle ntawm qhov teeb meem uas yuav tsis raug muab faib. English paub txog thiab naturalist, thiab D. Dalton muab ib tug txhais ntawm lub atom li qhov tsawg tshaj plaws ib feem ntawm ib tug tshuaj caij. MV Lomonosov nyob rau hauv nws cov atomic thiab molecular lus qhuab qhia yog muaj peev xwm muab ib tug txhais ntawm lub atom thiab molecule. Nws twb ntxias hais tias tus molecule, uas nws hu ua "corpuscles", muaj li ntawm "hais" - atoms - thiab yog nyob rau hauv qhov suab.

D. I. Mendeleev ntseeg hais tias qhov no subunit tshuaj uas ua tau cov ntaub ntawv uas lub ntiaj teb no, retains tag nrho nws lub zog tsuas yog hais tias nws yog tsis raug mus rau division. Nyob rau hauv no tsab xov xwm, peb txhais tau ib yam twj paj nruas raws li ib tug microcosm ntawm lub atom, thiab kawm nws cov khoom.

Tom qab ntawm cov kev tshawb xav ntawm atomic qauv

Nyob rau hauv lub xyoo pua puv 19, nws yog dav pom zoo raws li cov nqe lus nyob rau hauv lub indivisibility ntawm lub atom. Feem ntau cov zaum ntseeg tias tus hais ntawm ib tug tshuaj caij nyob rau hauv txhua yam yuav tsis tau transformed rau hauv atoms ntawm lwm yam hais. Cov tswv yim twb lub hauv paus uas yog raws li lub ntsiab txhais ntawm ib tug atom kom txog rau thaum 1932. Nyob rau hauv lub lig puv 19 xyoo pua nyob rau hauv science tau ua yuav tsum muaj discoveries uas hloov qhov no saib. Ua ntej ntawm tag nrho cov, nyob rau hauv 1897 lub British physicist J. J. Thomson nrhiav tau lub electron. Qhov tseeb yog fundamentally hloov zaum lub tswv yim hais txog indivisible ib feem ntawm cov tshuaj lub caij.

Yuav ua li cas los ua pov thawj hais tias tus atom complex qauv

Txawm tias ua ntej lub foundations ntawm cov electron , zaum tej yam ua ke pom zoo tias tus atoms muaj tsis tau them nqi. Ces, nws pom hais tias electrons yog yooj yim distinguished los ntawm tej yam tshuaj caij. Lawv muaj peev xwm yuav nrhiav tau nyob rau hauv ib tug nplaim taws, lawv yog nqa ntawm hluav taws xob tam sim no, lawv tso tshuaj thaum lub sij hawm x-ray tawg.

Tab sis yog hais tias tus electrons yog ib feem ntawm tag nrho cov tsis muaj kev zam, thiab tsis zoo them atoms, yog li, nyob rau hauv ib tug atom muaj ib co hais uas yeej paub hais tias muaj ib tug zoo xwb, txwv tsis pub atoms yuav tsis tau electrically nruab nrab. Yuav kom pab unravel cov qauv ntawm cov atom tau pab ib lub cev tshwm sim raws li radioactivity. Nws muab qhov tseeb ntsiab txhais ntawm lub atom nyob rau hauv physics, thiab ces Science News for KIDS.

Lub pom rays

Fabkis physicist A. Becquerel yog thawj los piav cov phenomenon ntawm emission ntawm atoms ntawm ib co tshuaj hais, visually pom rays. Lawv ionize cov huab cua pass los ntawm cov khoom, uas yuav ua tau blackening ntawm photographic daim hlau. Tom qab ntawd, lub Curies thiab Rutherford pom tias tej tshuaj uas hloov mus rau hauv atoms ntawm lwm yam tshuaj hais (xws li uranium - neptunium).

Tej tawg yog nonuniform nyob rau hauv muaj pes tsawg leeg: alpha hais, beta hais, gamma rays. Yog li, lub phenomenon ntawm radioactivity muaj pov thawj hais tias tus periodic rooj hais hais muaj ib tug complex qauv. Qhov tseeb tshwm sim los ntawm kev hloov mus rau lub ntsiab txhais ntawm lub atom. Yuav ua li cas hais yog ib qho atom, muab los ntawm Rutherford tau tshiab kev tseeb? Lo lus teb rau lo lus nug no yog cov lus kawm nuclear qauv ntawm lub atom, raws li uas nyob ib ncig ntawm lub zoo-them nucleus electrons txav.

Contradictions Rutherford qauv

Lub hom phiaj ntawm tus paub txog, txawm nws zoo ua luaj ua cim, yuav tsis objectively txhais tau lub atom. Nws nrhiav tau tooj mus rau yuav tsum muaj kev cai lij choj ntawm thermodynamics, raws li uas tag nrho cov electrons orbiting lub nuclei poob lawv lub zog thiab, raws li nws tej zaum yuav, ntxov los yog tom qab muaj los poob rau nws. Atom nyob rau hauv cov ntaub ntawv no puas lawm. Qhov no yog ua tau tsis yog cov ntaub, txij li thaum cov tshuaj thiab hais los ntawm uas lawv ua, muaj nyob rau hauv cov xwm rau ib ntev lub sij hawm. Inexplicably atom xws txiav txim raws li cov kev tshawb xav ntawm Rutherford, raws li zoo raws li lub phenomenon uas tshwm sim thaum dua kub yooj yim tshuaj los ntawm ib tug diffraction grating. Tom qab atomic spectra tsim nyob rau tib lub sij hawm muaj ib tug linear zoo. Qhov no conflicted nrog lub Rutherford qauv ntawm lub atom, raws li uas tus spectrum yuav yuav tsum tau tas mus li. Raws li lub ntsiab ntawm quantum mechanics, electrons tam sim no nyob rau hauv lub nucleus tsis yus li taw tes khoom raws li muaj hauv daim ntawv ntawm cov electron huab.

Feem ntau ntawm nws ceev nyob rau hauv ib tug tej yam locus ntawm qhov chaw ib ncig ntawm lub keeb, thiab yog pom tias yuav tsum tau qhov chaw ntawm ib tug particle ntawm ib lub sij hawm. Tsis tas li ntawd, nws twb pom hais tias cov atom, electrons cov txheej txheem ntawm nyob rau hauv khaubncaws sab nraud povtseg. Cov nab npawb ntawm cov khaubncaws sab nraud povtseg yuav tsum tau txiav txim los ntawm kev paub txog cov xov tooj ntawm lub sij hawm nyob rau hauv uas lub caij nyob rau hauv lub Periodic D. I. Mendeleeva System. Piv txwv li, lub phosphorus atom muaj 15 electrons thiab muaj peb lub zog ntau. Cov qhov taw qhia, uas txiav txim tus xov tooj ntawm lub zog ntau yog hu ua tus thawj xib fwb quantum tooj.

Nws yog tsim los experimentally hais tias tus muaj zog ntawm electrons, nyob ze tshaj rau tus tub ntxhais, muaj tus nqi qis tshaj zog. Txhua lub zog plhaub yog muab faib mus rau hauv sub-ntau ntau, thiab lawv, nyob rau hauv lem, nyob rau hauv orbitals. Electrons yog nyob rau ntawm txawv orbitals muaj tib lub daim ntawv huab (s, p, d, f).

Raws li cov foregoing, nws hais ntxiv hais tias tus duab ntawm lub electron huab yuav tsis tau arbitrary. Nws yog nruj me ntsis raws li qhov orbital quantum tooj. Peb ntxiv kuj tau hais tias lub xeev ntawm lub electron mus rau lub particulate yog tseem txiav txim los ntawm ob qhov tseem ceeb - magnetic thiab saws quantum xov tooj. Tus thawj yog raws li nyob rau hauv lub Schrodinger kab zauv thiab characterizes lub spatial orientation ntawm lub electron huab rau lub hauv paus ntawm lub peb-dimensionality ntawm peb lub ntiaj teb. Qhov thib ob qhov taw qhia - tus xov tooj ntawm tig rau nws txiav txim seb lub electron txoj kev tig ib ncig ntawm nws axis los yog counter-clockwise.

Tus foundations ntawm cov neutron

Los ntawm lub chaw ua hauj lwm ntawm D. Chadwick, tuav lawv nyob rau hauv 1932, nws tau muab ib tug tshiab ntsiab txhais ntawm lub atom nyob rau hauv Science News for KIDS thiab physics. Nyob rau hauv lawv scientific thwmsim nws muaj pov thawj hais tias nyob rau hauv lub cleavage tshwm sim polonium tawg tshwm sim los ntawm tus hais muaj tsis muaj nyiaj, tus loj 1,008665. Ib tug tshiab elementary particle lub npe hu ua lub neutron. Nws foundations thiab kawm txog nws cov khoom tau tso cai lub Soviet zaum V. Gapon thiab Ivanenko tsim ib tug tshiab kev tshawb xav ntawm cov qauv ntawm cov atomic nucleus, uas muaj protons thiab neutrons.

Raws li tus tshiab qhov kev tshawb xav, kev txiav txim rau yam khoom uas muaj cov nram qab no atom tsim ib tug yam ntxwv chav tsev ntawm cov tshuaj lub caij, muaj raws ntawm ib tug tub ntxhais uas muaj protons, neutrons thiab electrons tsiv nyob ib ncig ntawm nws. Cov nab npawb ntawm cov zoo hais nyob rau hauv lub nucleus yog yeej ib txwm sib npaug zos rau cov ordinal tooj ntawm cov tshuaj lub caij nyob rau hauv lub periodic system.

Tom qab ntawd cov xibfwb Zhdanov nyob rau hauv nws thwmsim paub tseeb tias nyob rau hauv tus ntawm ib qho nyuaj cosmic tawg, atomic nuclei yog phua rau hauv protons thiab neutrons. Nyob rau hauv tas li ntawd, nws tau raug muaj pov thawj hais tias cov rog tuav cov elementary hais nyob rau hauv lub nucleus, nws yog tsis tshua muaj zog-intensive. Lawv ua rau heev luv luv mus (ntawm qhov kev txiav txim ntawm 10 ^-23 cm), hu ua nuclear. Raws li hais ua ntej lawm, los ntawm MV Lomonosov yog muaj peev xwm muab ib tug txhais ntawm lub atom thiab cov molecule rau lub hauv paus ntawm kev tseeb paub rau nws.

Tam sim no pom tau hais tias xav txog cov nram qauv: atom muaj ib tug nucleus thiab electrons tsiv nyob ib ncig ntawm nws nyob rau hauv ib tug ncaj qha txhais paths - orbitals. Electrons nyob rau tib lub sij hawm muaj lub zog ntawm ob lub hais thiab tsis, uas yog, muaj ib tug dual xwm. Lub keeb ntawm ib tug atom yog feeb meej yuav luag tag nrho nws cov loj. Nws muaj protons thiab neutrons txuam nrog nuclear rog.

Seb nws puas yuav tau luj atom

Nws hloov tawm hais tias txhua atom muaj loj. Piv txwv li, nws yog ib yam uas Hydrogen 1,67h10 ^-24 txawm nyuaj rau xav txog tej yam me me li cas no tus nqi. Yuav kom nrhiav tau tus luj ntawm tus kwv, tsis txhob siv cov dos, thiab cov oscillator, uas yog ib tug carbon nanotube. Yuav kom xam tus luj ntawm lub atom thiab cov molecule ntau yooj yim kom muaj nuj nqis yog cov txheeb ze ceeb thawj. Nws qhia tau hais tias yuav ua li cas muaj ntau zaus tus luj ntawm lub molecule los yog ib tug atom ntau tshaj 1/12 ntawm cov pa roj carbon atom, uas yog 1,66h10 ^-27 kg. Tus kwv tij atomic masses yog muab nyob rau hauv lub periodic rooj ntawm tshuaj hais, thiab lawv tsis muaj dimension.

Zaum yeej paub zoo txog tias cov atomic luj ntawm lub tshuaj lub caij - yog qhov nruab nrab loj tus naj npawb ntawm isotopes. Nws zoo nkaus li, nyob rau hauv lub qhov ntawm ib tug tsev ntawm ib tug tshuaj caij tej zaum yuav muaj ntau pawg. Yog li cov nqi ntawm cov nuclei ntawm xws ntxwv particle tib.

Zaum tau pom hais tias tus isotopes txawv nyob rau hauv tus naj npawb ntawm neutrons nyob rau hauv lub nucleus thiab nuclei them lawv tib yam. Piv txwv li, ib tug tshuaj atom, muaj ib tug loj 35 muaj 18 neutrons thiab 17 protons, thiab nrog ib tug loj ntawm 37 - 20 protons thiab 17 neutrons. Muaj ntau cov tshuaj hais yog mixtures ntawm isotopes. Piv txwv li, tej yam yooj yim tshuaj xws li poov tshuaj, argon, oxygen muaj nyob rau hauv nws muaj pes tsawg leeg atoms sawv cev 3 txawv isotope.

Kev txiav txim ntawm atomicity

Nws muaj ob peb txhais. Xav txog dab tsi yog meant ntawm no lub sij hawm nyob rau hauv Science News for KIDS. Yog hais tias lub atoms ntawm ib tug tshuaj caij yuav tsawg kawg yog ib pliag nyob rau hauv kev rho tawm, tsis yuav daim ntawv ntau hais - molecules, ces peb hais tias xws li tej yam tshuaj muaj ib tug atomic qauv. Piv txwv li, multi-theem chlorination cov tshuaj tiv thaiv ntawm methane. Nws yog dav siv nyob rau hauv cov organic hluavtaws Science News for KIDS rau cov loj halogen derivatives: dichloromethane, carbon tetrachloride. Nws yog phua tshuaj molecules rau atoms muaj siab reactivity. Lawv puas sigma bonds nyob rau hauv lub methane molecule, muab ib cov saw hloov cov tshuaj tiv thaiv.

Lwm cov piv txwv ntawm ib tug tshuaj txheej txheem muaj zoo tseem ceeb nyob rau hauv lub lag luam - kev siv cov hydrogen peroxide raws li ib tug tshuaj tua kab mob thiab tshuaj dawb tso tus neeg saib xyuas. Kev txiav txim ntawm atomic oxygen raws li ib tug cleavage khoom ntawm hydrogen peroxide tshwm sim nyob rau hauv ob qho tib si nyob hlwb (los ntawm cov enzyme catalase), thiab nyob rau hauv txoj kev kuaj. Atomic oxygen qualitatively txiav txim los ntawm nws cov high antioxidant zog thiab lawv muaj peev xwm ua kom puas pathogenic cov kab mob: kab mob, fungi thiab lawv muaj cov noob.

Yuav ua li cas lub nuclear lub hnab ntawv

Peb tau yav tas los pom hais tias tus yam ntxwv chav tsev ntawm ib tug tshuaj caij muaj ib tug complex qauv. Nyob ib ncig ntawm lub zoo-them nucleus hais tig tsis zoo electrons. Lub Nobel nqi zog Niels Bohr, raws li nyob rau hauv quantum kev tshawb xav ntawm lub teeb, tsim ib tug qhia ntawv, nyob rau lub characterization thiab qhia kom paub txog atoms yog raws li nram no: electrons tsiv nyob ib ncig ntawm lub keeb tsuas yog nyob rau tej yam tas paths nyob rau hauv cov ntaub ntawv no tsis radiate zog. Bohr, zaum tau qhia tias tus hais ntawm lub microworld, uas muaj xws li atoms thiab molecules tsis ua raws li cov kev cai siv tau rau cov loj lub cev - khoom macrocosm.

Tus qauv ntawm lub electron zoo li ntawm particulates tau raug kawm nyob rau hauv cov ntaub ntawv nyob rau hauv quantum physics zaum xws li Hund, Pauli Klechkovskii. Txij li thaum nws los ua npe hu hais tias lub electrons ua lub muab tsab ntawv tsa suab nyob ib ncig ntawm lub keeb yog tsis chaotic, tab sis nyob rau tej yam tas paths. Pauli pom tias nyob rau hauv ib zaug xwb muaj zog ntawm txhua yam ntawm nws orbitals s, p, d, f nyob rau hauv hluav taws xob hlwb tej zaum yuav tsis muaj ntau tshaj li ob tsis zoo them hais ntawm opposite kiv nqi + ½ thiab - ½.

Hund kav piav yuav ua li cas sau electron orbitals nrog lub qub zog lawm.

Aufbau hauv paus ntsiab lus, kuj hu ua txoj cai n + l, piav qhia txog yuav ua li cas sau orbitals multielectron atoms (ntsiab 5, 6, 7 mus). Tag nrho cov saum toj no regularities tau txais kev pab raws li lub theoretical lub hauv paus ntawm tshuaj ntsiab tsim los ntawm Dmitriem Mendeleevym.

oxidation degree

Nws yog ib tug yuav tsum muaj tswvyim nyob rau hauv Science News for KIDS thiab piav lub xeev ntawm ib tug atom nyob rau hauv ib tug qauv. Cov niaj hnub ntsiab txhais ntawm lub degree ntawm oxidation ntawm lub atoms yog raws li nram no: tus nqi yog conditioned atoms nyob rau hauv lub molecule, uas yog xam raws li cov tswv yim hais tias ib tug qauv muaj tsuas yog tus ionic muaj pes tsawg leeg.

Cov oxidation yuav qhia los ntawm ib tug zauv los yog ib tug fractional tooj, ib tug zoo, tsis zoo los yog pes tsawg qhov tseem ceeb. Nyob rau hauv feem ntau atoms ntawm tshuaj ntsiab muaj ob peb oxidation lub xeev. Piv txwv li, nitrogen yog -3, -2, 0, +1, +2, +3, +4, +5. Tab sis xws li ib tug caij, xws li fluorine, nyob rau hauv tag nrho cov ntawm nws cov tebchaw muaj tsuas yog ib oxidation lub xeev sib npaug zos rau -1. Yog hais tias nws yog hais ib tug yooj yim tshuaj, nws oxidation lub xeev ntawm xoom. Qhov no tshuaj ntau yooj yim rau siv rau cov kev faib ntawm tshuaj thiab piav qhia txog lawv lub zog. Nyob rau hauv Feem ntau, lub oxidation degree ntawm cov Science News for KIDS siv nyob rau hauv qhov chaw kawm mus sib npaug redox tshua.

Cov khoom ntawm atoms

Tsaug rau lub discoveries ntawm quantum physics, cov niaj hnub ntsiab txhais ntawm lub atom, uas yog raws li nyob rau hauv cov kev tshawb xav Ivanenko thiab Gapon E, supplemented los ntawm cov nram qab no kev tseeb. Tus qauv ntawm ib tug atomic nucleus yog tsis tau hloov lub sij hawm cov tshuaj tshua. Cov kev hloov feem xyuam rau tsuas yog tus nyob ruaj ruaj electron orbitals. Lawv cov qauv yuav tsum tau ntaus nqi mus rau ib tug ntau ntawm lub cev thiab tshuaj thaj chaw ntawm tshuaj. Yog hais tias lub electron yoojyim ib tug nyob ruaj ruaj orbit thiab hais kom orbital nrog ib tug ntau dua lub zog xws atom yog hu ua pog.

Nws yuav tsum tau muab sau tseg tias electrons yuav ua tsis tau ib tug ntev lub sij hawm nyob rau hauv cov uas tsis yog-tub ntxhais orbitals. Rov qab mus rau nws ruaj ruaj orbit, lub electron emits lub quantum ntawm lub zog. Txoj kev tshawb no ntawm tej yam ntxwv ntawm lub structural units ntawm tshuaj ntsiab raws li electron affinity, electronegativity, ionization zog, tau tso cai rau zaum tsis tau tsuas yog txhais tau cov atom ib qho tseem ceeb particle microcosm, tab sis kuj tso cai rau lawv los mus piav qhia cov kev muaj peev xwm ntawm atoms mus ua ib lub ruaj khov thiab energetically ntau paaj molecular lub xeev ntawm teeb meem, ib tug ua tau tsim nyog tau kev tsim txhua yam uas ruaj khov tshuaj bonds: ionic, covalent-polar thiab apolar, pub-acceptor (raws li covalent tsevneeg hom) thiab m etallicheskoy. Cov yav tas thiab txiav txim seb lub tseem ceeb tshaj plaws lub cev thiab tshuaj thaj chaw ntawm hlau.

Nws yog tsim los experimentally hais tias cov loj ntawm ib tug atom yuav txawv. Tag nrho yuav yog nyob ntawm seb molecule nyob rau hauv uas nws muaj. Los ntawm X-hluav taws xob diffraction tsom xam yuav xam qhov kev ncua deb ntawm atoms nyob rau hauv ib tug tshuaj compound, raws li zoo raws li kawm voos kheej-kheej cov yam ntxwv caij unit. Owning qauv ntawm kev hloov ntawm radii ntawm lub atoms muaj nyob rau hauv lub sij hawm los yog cov pab pawg neeg ntawm cov tshuaj hais, nws yog ua tau rau koj twv seb lawv lub cev thiab tshuaj zog. Piv txwv li, nyob rau hauv sij hawm nrog ua atomic nucleus them lawv radii txo ( "compression atom"), thiab yog li ntawd tsis muaj zog hauv lub nws yog xim hlau thaj chaw ntawm lub tebchaw, thiab nonmetallic amplified.

Yog li, kev txawj ntse ntawm cov qauv ntawm cov atom yuav meej txiav txim lub cev thiab tshuaj thaj chaw ntawm tag nrho cov ntsiab muaj nyob rau hauv lub periodic system ntawm hais.