Nrog lub atom mus txog hnub nyoog - part 3

Rutherford's planetary qauv ntawm lub atom yog ze rau qhov tseeb dua Thomson's "raisin pudding". Txawm li cas los xij, lub neej ntawm lub tswv yim no tsuas yog ob xyoos xwb, tab sis ua ntej tham txog tus neeg ua tiav, nws yog lub sijhawm los nthuav tawm cov lus zais tom ntej atomic.

1. Isotopes ntawm hydrogen: ruaj khov prot thiab deuterium thiab radioactive tritium (duab: BruceBlaus/Wikimedia Commons).

Atomic avalanche

Lub discovery ntawm lub phenomenon ntawm radioactivity, uas cim qhov pib ntawm unraveling mysteries ntawm lub atom, pib hem lub hauv paus ntawm chemistry - txoj cai ntawm periodicity. Nyob rau hauv ib lub sij hawm luv luv, ob peb lub kaum os radioactive tshuaj raug txheeb xyuas. Qee tus ntawm lawv muaj tib yam tshuaj lom neeg, txawm tias sib txawv atomic masses, thaum lwm tus, nrog tib pawg, muaj cov khoom sib txawv. Ntxiv mus, nyob rau hauv lub cheeb tsam ntawm lub periodic rooj uas lawv yuav tsum tau muab tso rau vim lawv qhov hnyav, tsis muaj qhov chaw dawb txaus los haum rau lawv txhua tus. Lub sij hawm lub sij hawm tau ploj vim muaj avalanche ntawm discoveries.

2. Replica ntawm 1911 J. J. Thompson mass spectrometer (duab: Jeff Dahl / Wikimedia Commons)

Atomic nucleus

Qhov no yog 10-100 txhiab. lub sij hawm me dua tag nrho cov atom. Yog hais tias lub nucleus ntawm hydrogen atom tau loj mus rau qhov loj ntawm lub pob nrog ib txoj kab uas hla ntawm 1 cm thiab muab tso rau hauv nruab nrab ntawm ib tug football teb, ces lub electron (me dua lub taub hau ntawm tus pin) yuav xaus nyob rau hauv ib ncig ntawm lub hom phiaj (tshaj 50 m).

Yuav luag tag nrho cov loj ntawm ib lub atom yog concentrated nyob rau hauv lub nucleus; piv txwv li, rau kub nws yog yuav luag 99,98%. Xav txog ib lub voos xwmfab ntawm cov hlau no hnyav 19,3 tons. Tag nrho atomic nuclei kub muaj tag nrho cov ntim tsawg dua 1/1000 mm3 (ib lub pob nrog lub cheeb ntawm tsawg dua 0,1 mm). Yog li ntawd, lub atom yog heev khoob. Cov neeg nyeem yuav tsum suav qhov ntom ntawm cov khoom hauv qab.

Txoj kev daws teeb meem no tau pom nyob rau xyoo 1910 los ntawm Frederick Soddy. Nws qhia txog lub tswvyim ntawm isotopes, i.e. ntau yam ntawm tib lub caij uas txawv ntawm lawv cov atomic mass (1). Yog li, nws tau nug lwm tus ntawm Dalton's postulates - txij li tam sim no mus, cov tshuaj lom neeg yuav tsum tsis muaj cov atoms ntawm tib pawg. Lub isotope hypothesis, tom qab kev sim kev pom zoo (mass spectrograph, 1911), kuj ua rau nws muaj peev xwm piav qhia txog qhov tseem ceeb ntawm cov atomic masses ntawm qee lub ntsiab lus - feem ntau ntawm lawv yog cov sib xyaw ntawm ntau cov isotopes, thiab atomic loj yog qhov hnyav nruab nrab ntawm cov pawg ntawm txhua tus ntawm lawv (2).

Kernel Cheebtsam

Lwm tus ntawm Rutherford cov tub ntxhais kawm, Henry Moseley, kawm X-rays tawm los ntawm cov ntsiab lus paub hauv xyoo 1913. Tsis zoo li txoj kev kho qhov muag pom kev, X-ray spectrum yog qhov yooj yim heev - txhua lub ntsiab lus tsuas yog ob lub nthwv dej, qhov ntev uas yooj yim cuam tshuam rau tus nqi ntawm nws cov atomic nucleus.

3. Ib lub tshuab X-ray siv los ntawm Moseley (duab: Magnus Manske / Wikimedia Commons)

Qhov no ua rau nws ua tau rau thawj zaug los nthuav qhia tus naj npawb ntawm cov ntsiab lus uas muaj nyob, nrog rau kev txiav txim siab seb muaj pes tsawg tus ntawm lawv tseem tsis tau sau cov khoob hauv lub sijhawm (3).

Cov khoom uas nqa cov nqi zoo yog hu ua proton (Greek: proton = thawj). Lwm qhov teeb meem tam sim ntawd tshwm sim. Qhov loj ntawm ib tug proton yog kwv yees li 1 units. Qhov twg atomic nucleus sodium nrog tus nqi ntawm 11 units muaj qhov loj ntawm 23 units? Tib yam yog, ntawm chav kawm, rooj plaub nrog lwm yam. Qhov no txhais tau hais tias yuav tsum muaj lwm cov khoom muaj nyob hauv cov nucleus uas tsis muaj nqi. Thaum xub thawj, physicists xav tias cov no tau nruj nreem khi protons nrog electrons, tab sis thaum kawg nws tau ua pov thawj tias ib qho tshiab tau tshwm sim - cov neutron (Latin neuter = nruab nrab). Qhov kev tshawb pom ntawm cov ntsiab lus tseem ceeb no (lub npe hu ua "lub tsev thaiv" uas txhua yam muaj nyob hauv) tau tsim nyob rau xyoo 1932 los ntawm Askiv tus kws kho mob James Chadwick.

Protons thiab neutrons tuaj yeem hloov mus rau ib leeg. Physicists theorize tias lawv yog cov ntaub ntawv ntawm ib tug particle hu ua ib tug nucleon (Latin nucleus = nucleus).

Txij li thaum lub nucleus ntawm qhov yooj yim tshaj plaws isotope ntawm hydrogen yog ib tug proton, nws yog tseeb hais tias William Prout nyob rau hauv nws "hydrogen" hypothesis kev tsim kho atomic nws tsis yuam kev lawm (saib: “Nrog lub atom mus txog ntau pua xyoo – part 2”; “Young Technician” No. 8/2015). Thaum xub thawj muaj kev tsis txaus siab ntawm cov npe proton thiab "prouton".

4. Photocells ntawm qhov kawg - lawv txoj haujlwm yog raws li cov nyhuv photoelectric (duab: Ies/Wikimedia Commons)

Tsis yog txhua yam tso cai

Rutherford tus qauv muaj "kev yug me nyuam" thaum lub sijhawm qhia. Raws li Maxwell txoj cai lij choj ntawm electrodynamics (kev lees paub los ntawm xov tooj cua tshaj tawm uas twb muaj lawm nyob rau lub sijhawm ntawd), lub tshuab hluav taws xob txav mus rau hauv lub voj voog yuav tsum emit ib tug electromagnetic yoj.

Yog li, nws poob lub zog, ua rau nws poob rau hauv lub hauv paus. Nyob rau hauv ib txwm muaj, atoms tsis emit (spectra yog tsim thaum rhuab mus rau high kub) thiab atomic catastrophes tsis pom (qhov kwv yees lub neej ntawm ib tug electron yog tsawg tshaj li ib lab ntawm ib tug thib ob).

Rutherford tus qauv piav qhia qhov tshwm sim ntawm qhov kev sim particle tawg, tab sis tseem tsis tau raws li qhov tseeb.

Xyoo 1913, tib neeg "tau siv" qhov tseeb tias lub zog hauv microcosm raug coj mus thiab xa tsis yog nyob rau hauv ib qho, tab sis nyob rau hauv feem hu ua quanta. Raws li lub hauv paus no, Max Planck tau piav qhia txog qhov xwm txheej ntawm cov hluav taws xob hluav taws xob tawm los ntawm lub cev kub (1900), thiab Albert Einstein (1905) tau piav qhia cov secrets ntawm cov nyhuv photoelectric, piv txwv li cov emission ntawm electrons los ntawm illuminated hlau (4).

5. Daim duab diffraction ntawm electrons ntawm tantalum oxide siv lead ua qhia nws cov qauv sib luag (duab: Sven.hovmoeller/Wikimedia Commons)

28-xyoo-laus Danish physicist Niels Bohr txhim kho Rutherford tus qauv ntawm lub atom. Nws tau hais tias cov khoom siv hluav taws xob tsuas yog txav mus rau hauv orbits uas ua tau raws li qee lub zog. Tsis tas li ntawd, electrons tsis tawm hluav taws xob thaum tsiv, thiab lub zog yog absorbed thiab emissions tsuas yog thaum shunting ntawm orbits. Cov kev xav tau contradicted classical physics, tab sis cov txiaj ntsig tau los ntawm lawv lub hauv paus (qhov loj ntawm hydrogen atom thiab qhov ntev ntawm cov kab ntawm nws cov spectrum) tau ua raws li kev sim. Ib tug tshiab yug qauv atom.

Hmoov tsis zoo, cov txiaj ntsig tsuas yog siv tau rau hydrogen atom (tab sis tsis tau piav qhia tag nrho cov kev soj ntsuam spectral). Rau cov ntsiab lus ntxiv, cov txiaj ntsig suav tsis sib haum rau qhov tseeb. Yog li, physicists tseem tsis tau muaj tus qauv theoretical ntawm lub atom.

Cov secrets pib ua kom pom tseeb tom qab kaum ib xyoos. Cov kws kho mob hais tawm ntawm Fab Kis tus kws kho mob Ludwick de Broglie txhawj xeeb txog yoj lub zog ntawm cov khoom siv. Nws twb tau raug pov thawj tias lub teeb, ntxiv rau cov yam ntxwv ntawm nthwv dej (diffraction, refraction), kuj coj zoo li cov khoom sib sau ua ke - photons (piv txwv li, kev sib tsoo elastic nrog electrons). Tab sis cov khoom loj? Qhov kev xav zoo li lub yeeb nkab npau suav rau tus tub huabtais, uas xav ua tus kws kho mob. Txawm li cas los xij, xyoo 1927, kev sim tau ua tiav uas tau lees paub tias de Broglie qhov kev xav - cov kwj ntawm cov hluav taws xob sib txawv ntawm cov hlau siv lead ua (5).

Atoms tuaj qhov twg?

Zoo li txhua leej txhua tus: Lub Big Bang. Physicists ntseeg hais tias cov lus nyob rau hauv ib feem ntawm ib tug thib ob los ntawm lub "zero point" protons, neutrons thiab electrons tau tsim, uas yog, lub constituent atoms. Tom qab ob peb feeb (raws li lub ntiaj teb txias thiab qhov ntom ntawm cov teeb meem txo qis), cov nucleons fused ua ke los tsim cov nuclei ntawm cov ntsiab lus uas tsis yog hydrogen. Qhov loj tshaj plaws ntawm helium tau tsim, nrog rau cov kab ntawm peb lub ntsiab lus tom ntej. Nws tsuas yog tom qab 100 xyoo uas cov xwm txheej ua rau nws tuaj yeem khi electrons rau nuclei - thawj atoms tau tsim. Peb yuav tsum tau tos ntev heev rau cov tom ntej. Random fluctuations nyob rau hauv ceev ua rau tsim ntawm ntom, uas, raws li lawv tshwm sim, attracted ntau thiab ntau teeb meem. Tsis ntev ces cov thawj hnub qub tau tshwm sim hauv qhov tsaus ntuj ntawm lub Ntiaj Teb.

Tom qab txog ib txhiab xyoo, ib txhia pib tuag. Nyob rau hauv lawv cov chav kawm lawv tsim atomic nuclei txoj cai mus rau hlau. Tam sim no, thaum lawv tuag, lawv kis tau thoob plaws hauv cheeb tsam, thiab cov hnub qub tshiab tau yug los ntawm cov tshauv. Qhov loj tshaj plaws ntawm lawv muaj qhov kawg spectacular. Thaum lub sij hawm supernova tawg, lub nuclei tau tawg nrog ntau qhov hais tias txawm tias cov ntsiab lus hnyav tshaj plaws tau tsim. Los ntawm lawv cov hnub qub tshiab, ntiaj chaw, thiab ntawm qee lub ntiaj teb - lub neej raug tsim.

Lub hav zoov ntawm cov teeb meem nthwv dej tau raug pov thawj. Ntawm qhov tod tes, ib qho hluav taws xob hauv ib lub atom tau suav tias yog lub zog sawv ntsug, vim nws tsis tawg lub zog. Cov khoom nthwv dej ntawm cov hluav taws xob txav tau siv los tsim cov tshuab hluav taws xob, tso cai rau cov atoms pom thawj zaug (6). Nyob rau xyoo tom ntej, kev ua haujlwm ntawm Werner Heisenberg thiab Erwin Schrödinger (raws li de Broglie's hypothesis) tau tso cai rau kev tsim kho tshiab, tag nrho cov qauv ntawm lub plhaub hluav taws xob ntawm lub atom. Tab sis cov no yog cov lus nug dhau ntawm cov kab lus no.

Kev npau suav ntawm alchemists tau los txog

Kev hloov pauv hluav taws xob ntuj, thaum lub sijhawm tsim cov ntsiab lus tshiab, tau paub txij li thaum kawg ntawm xyoo 1919th. Hauv XNUMX, ib yam dab tsi uas tsuas yog qhov muaj peev xwm mus txog rau tam sim no. Thaum lub sijhawm no, Ernest Rutherford tau kawm txog kev cuam tshuam ntawm cov khoom nrog cov teeb meem. Thaum kuaj, nws pom tias protons tshwm sim los ntawm irradiation nrog nitrogen gas.

Qhov kev piav qhia nkaus xwb rau qhov tshwm sim yog cov tshuaj tiv thaiv ntawm helium nuclei (ib qho thiab nucleus ntawm ib qho isotope ntawm lub caij no) thiab nitrogen (7). Yog li ntawd, oxygen thiab hydrogen yog tsim (proton yog lub nucleus ntawm lub teeb tshaj isotope). Cov alchemists 'kev npau suav ntawm transmutation tau los txog. Hauv kaum xyoo tom ntej, cov khoom raug tsim tawm uas tsis tshwm sim hauv qhov xwm txheej.

Cov khoom siv hluav taws xob hauv ntuj tsim tawm alpha hais tsis haum rau lub hom phiaj no lawm (Lub Coulomb barrier ntawm hnyav nuclei loj heev rau lub teeb particle mus rau lawv). Accelerators uas muab lub zog loj rau lub nuclei ntawm cov isotopes hnyav dhau los ua "alchemical furnaces" uas cov poj koob yawm txwv ntawm cov kws tshuaj niaj hnub no tau sim kom tau txais "tus huab tais ntawm cov hlau" (8).

Qhov tseeb, ua li cas txog kub? Alchemists feem ntau siv mercury ua raw khoom rau nws cov khoom. Nws yuav tsum raug lees paub tias nyob rau hauv rooj plaub no lawv muaj "qhov ntswg" tiag tiag. Nws yog los ntawm mercury kho nrog neutrons nyob rau hauv ib tug nuclear reactor uas dag dag yog thawj zaug. Daim hlau tau pom nyob rau xyoo 1955 ntawm Geneva Atomic Conference.

6. Atoms nyob rau saum npoo ntawm kub, pom nyob rau hauv ib tug scanning tunneling microscope duab.

7. Scheme ntawm thawj tib neeg transmutation ntawm lub ntsiab

Cov xov xwm ntawm physicists 'kev ua tau zoo txawm tias ua rau lub sijhawm luv luv ntawm kev sib pauv hauv ntiaj teb, tab sis cov ntaub ntawv xov xwm sensational tau tsis lees paub los ntawm cov ntaub ntawv hais txog tus nqi ntawm cov ore mined nyob rau hauv txoj kev no - nws yog ntau zaus kim dua li ntuj kub. Cov reactors yuav tsis hloov lub pob zeb muaj nuj nqis. Tab sis cov isotopes thiab cov khoom tsim tawm hauv lawv (rau cov hom phiaj ntawm cov tshuaj, lub zog, kev tshawb fawb tshawb fawb) muaj txiaj ntsig ntau dua li kub.

8. Lub keeb kwm cyclotron synthesizing thawj ob peb lub ntsiab tom qab uranium nyob rau hauv lub periodic rooj (Lawrence Radiation Laboratory, University of California, Berkeley, Lub yim hli ntuj 1939)

Rau cov neeg nyeem uas xav tshawb txog cov teeb meem uas tau tsa hauv cov ntawv nyeem, kuv pom zoo kom cov kab lus los ntawm Mr. Tomasz Sowiński. Tau tshwm sim hauv "Young Technique" hauv 2006-2010 (hauv ntu "Yuav ua li cas thiaj nrhiav tau"). Cov ntawv tseem muaj nyob rau ntawm tus sau lub vev xaib ntawm: .

Lub voj voogNrog ib tug atom rau centuries“Kuv pib nrog kev ceeb toom tias ib puas xyoo dhau los feem ntau hu ua lub hnub nyoog ntawm atom. Tau kawg, ib tus tsis tuaj yeem tsis nco qab qhov kev ua tiav ntawm physicists thiab chemists ntawm lub xyoo pua XNUMX hauv cov qauv ntawm cov teeb meem. Txawm li cas los xij, nyob rau xyoo tas los no, kev paub txog microworld tau nthuav dav sai thiab nrawm dua, thiab cov thev naus laus zis tau tsim los ua kom nws muaj peev xwm tswj hwm tus kheej atoms thiab molecules. Qhov no ua rau peb muaj cai hais tias lub hnub nyoog tiag tiag ntawm lub atom tseem tsis tau los txog.