Nge-athomu phakathi neminyaka - ingxenye 3
Okuqukethwe
Imodeli yeplanethi kaRutherford ye-athomu yayiseduze neqiniso kune-"raisin pudding" kaThomson. Kodwa-ke, impilo yalo mqondo yahlala iminyaka emibili kuphela, kodwa ngaphambi kokukhuluma ngomlandeli, sekuyisikhathi sokudalula izimfihlo ze-athomu ezilandelayo.
1. Ama-Isotopes e-hydrogen: i-prot ezinzile ne-deuterium ne-radioactive tritium (isithombe: BruceBlaus/Wikimedia Commons).
I-avalanche ye-athomu
Ukutholakala kokwenzeka kwe-radioactivity, okwaphawula ukuqala kokwembula izimfihlakalo ze-athomu, ekuqaleni kwasongela isisekelo samakhemikhali - umthetho we-periodicity. Ngesikhashana nje, kwatholakala inqwaba yezinto ezikhipha imisebe. Ezinye zazo zazinamakhemikhali afanayo, naphezu kobuningi be-athomu obuhlukene, kuyilapho ezinye, ezinobuningi obufanayo, zinezakhiwo ezihlukene. Ngaphezu kwalokho, endaweni yetafula le-periodic lapho bekufanele babekwe khona ngenxa yesisindo sabo, sasingekho isikhala esanele sokuhlalisa bonke. Ithebula le-periodic lilahlekile ngenxa yenqwaba yezinto ezitholakele.
2. Okufanayo kwe-1911 J. J. Thompson mass spectrometer (isithombe: Jeff Dahl / Wikimedia Commons)
I-nucleus ye-athomu
Lokhu yizinkulungwane eziyi-10-100. izikhathi ezincane kune-athomu yonke. Uma i-nucleus ye-athomu ye-hydrogen ibikhuliswa ibe ubukhulu bebhola enobubanzi obungu-1 cm futhi ibekwe phakathi nendawo yenkundla yebhola, khona-ke i-electron (encane kunenhloko yephini) yayizophelela endaweni umgomo (ngaphezu kwama-50 m).
Cishe yonke inqwaba ye-athomu igxile ku-nucleus; isibonelo, igolide cishe lingama-99,98%. Cabanga ngekhiyubhu yale nsimbi enesisindo esingamathani angu-19,3. Konke ama-athomu igolide linomthamo ophelele ongaphansi kuka-1/1000 mm3 (ibhola elinobubanzi obungaphansi kuka-0,1 mm). Ngakho-ke, i-athomu ayinalutho kakhulu. Abafundi kumele babale ukuminyana kwento engaphansi.
Isixazululo sale nkinga satholwa ngo-1910 nguFrederick Soddy. Wethula umqondo wama-isotopes, i.e. izinhlobo ze-elementi efanayo ehluka ngesisindo se-athomu (1). Ngakho-ke, wabuza enye ye-postulates ka-Dalton - kusukela manje kuqhubeke, into yamakhemikhali akufanele iphinde ibe nama-athomu esisindo esifanayo. I-isotope hypothesis, ngemva kokuqinisekiswa kokuhlolwa (i-mass spectrograph, 1911), nayo yenza kwaba nokwenzeka ukuchaza amanani amancane enqwaba ye-athomu yezakhi ezithile - iningi lazo liyingxube yama-isotopes amaningi, futhi isisindo se-athomu isilinganiso esilinganiselwe soquqaba lwabo bonke (2).
Izingxenye ze-Kernel
Omunye wabafundi bakaRutherford, uHenry Moseley, wahlola ama-X-ray akhishwa izakhi ezaziwayo ngo-1913. Ngokungafani ne-spectra eyinkimbinkimbi ye-optical, i-spectrum ye-X-ray ilula kakhulu - isici ngasinye sikhipha amagagasi amabili kuphela, ubude bawo buhlobene kalula nokushajwa kwe-nucleus yayo ye-athomu.
3. Omunye wemishini ye-X-ray esetshenziswa uMoseley (isithombe: Magnus Manske/Wikimedia Commons)
Lokhu kwenza kwaba nokwenzeka okokuqala ngqa ukwethula inani langempela lezakhi ezikhona, kanye nokunquma ukuthi zingaki kuzo ezisashoda ukuze kugcwaliswe izikhala kuthebula le-periodic table (3).
Izinhlayiya ezithwala inani eliqondile libizwa ngokuthi iproton (ngesiGreki: iproton = okokuqala). Kwavela enye inkinga ngokushesha. Isisindo seproton cishe iyunithi elingu-1. Nakuba i-nucleus ye-athomu i-sodium ene-charge yamayunithi ayi-11 inesisindo samayunithi angama-23? Kuyafana, kunjalo, kunjalo nakwezinye izakhi. Lokhu kusho ukuthi kufanele kube nezinye izinhlayiya ezikhona ku-nucleus ezingakhokhi lutho. Ekuqaleni, izazi ze-physics zazicabanga ukuthi lawa kwakungama-proton aboshwe ngokuqinile ngama-electron, kodwa ekugcineni kwafakazelwa ukuthi kwakuvele inhlayiya entsha - i-neutron (i-Latin neuter = neutral). Ukutholakala kwalesi zinhlayiya eziyisisekelo (okubizwa ngokuthi "izingqimba zokwakha" eziyisisekelo eziqukethe yonke into) kwenziwa ngo-1932 isazi sefiziksi esiyiNgisi uJames Chadwick.
Ama-proton nama-neutron angashintsha abe elinye. Izazi zesayensi yemvelo zithi ziyizinhlobo zezinhlayiyana okuthiwa i-nucleon (i-nucleus yesiLatini = nucleus).
Njengoba i-nucleus ye-isotope ye-hydrogen elula kunazo zonke iyiproton, kusobala ukuthi uWilliam Prout ku-hypothesis yakhe ethi "hydrogen". isakhiwo se-athomu wayengaphosisi kakhulu (bheka: “Nge-athomu phakathi namakhulu eminyaka - ingxenye 2”; “Uchwepheshe Omusha” No. 8/2015). Ekuqaleni kwakukhona ngisho nokungabaza phakathi kwamagama proton kanye "prouton".
4. Ama-Photocell ekugcineni - umsebenzi wawo usekelwe kumphumela wesithombe sikagesi (isithombe: Ies/Wikimedia Commons)
Akuvunyelwe konke
Imodeli kaRutherford “yayinesici sokuzalwa” ngesikhathi yethulwa. Ngokwemithetho kaMaxwell ye-electrodynamics (eqinisekiswa ukusakazwa komsakazo kakade kwase kusebenza ngaleso sikhathi), i-electron ehamba embuthanweni kufanele ikhiphe igagasi likagesi.
Ngakho-ke, ilahlekelwa amandla, ibangele ukuthi iwele emnyombweni. Ngaphansi kwezimo ezivamile, ama-athomu awakhiphi (i-spectra yakheka lapho kushiswa amazinga okushisa aphakeme) futhi izinhlekelele ze-athomu azibonwa (isikhathi sokuphila esilinganiselwe se-electron singaphansi kwesigidi esisodwa somzuzwana).
Imodeli kaRutherford yachaza umphumela wokuhlolwa kokuhlakazwa kwezinhlayiyana, kodwa namanje ayizange ihambisane neqiniso.
Ngo-1913, abantu "bajwayele" ukuthi amandla ku-microcosm athathwa futhi athunyelwe hhayi nganoma yiliphi inani, kodwa ezingxenyeni ezibizwa ngokuthi i-quanta. Ngalesi sisekelo, uMax Planck wachaza uhlobo lwe-spectra yemisebe ekhishwa imizimba eshisayo (1900), futhi u-Albert Einstein (1905) wachaza izimfihlo zomphumela we-photoelectric, okungukuthi ukukhishwa kwama-electron ngezinsimbi ezikhanyisiwe (4).
5. Isithombe se-diffraction sama-electron ku-tantalum oxide crystal sibonisa ukwakheka kwawo okulinganayo (isithombe: Sven.hovmoeller/Wikimedia Commons)
Isazi sefiziksi saseDenmark esineminyaka engu-28 uNiels Bohr sathuthukisa imodeli kaRutherford ye-athomu. Waphakamisa ukuthi ama-electron ahamba kuphela emizileni ehlangabezana nezimo ezithile zamandla. Ngaphezu kwalokho, ama-electron awakhiphi imisebe lapho ehamba, futhi amandla adonswa futhi akhishwe kuphela lapho eshunqa phakathi kwemizila. Ukucatshangelwa kwakungqubuzana ne-classical physics, kodwa imiphumela etholwe ngesisekelo sayo (ubukhulu be-athomu ye-hydrogen nobude bemigqa ye-spectrum yayo) yabonakala ihambisana nokuhlolwa. Kwazalwa omusha imodeli ye-atomu.
Ngeshwa, imiphumela yayivumeleke kuphela ku-athomu ye-hydrogen (kodwa ayizange ichaze konke ukubhekwa kwe-spectral). Kulezi zici ezisele, imiphumela yokubala ayizange ihambisane neqiniso. Ngakho, izazi zefiziksi zazingakakabi nayo imodeli yetiyori ye-athomu.
Izimfihlo zaqala ukucaca ngemuva kweminyaka eyishumi nanye. Umbhalo wobudokotela wesazi sefiziksi esingumFulentshi uLudwick de Broglie uphathelene nezakhiwo zamagagasi zezinhlayiya zezinto. Sekuvele kufakazelwe ukuthi ukukhanya, ngaphezu kwezici ezijwayelekile zegagasi (i-diffraction, refraction), futhi iziphatha njengeqoqo lezinhlayiya - ama-photons (isibonelo, ukungqubuzana okunwebekayo nama-electron). Kodwa izinto mass? Lokhu kucatshangelwa kwakubonakala njengephupho lenkosana, eyayifuna ukuba isazi se-physics. Kodwa-ke, ngo-1927, kwenziwa ucwaningo olwaqinisekisa umbono ka-de Broglie - umfudlana wama-electron ahlukanisiwe kukristalu lensimbi (5).
Avelaphi ama-athomu?
Njengawo wonke umuntu: I-Big Bang. Izazi zefiziksi zikholelwa ukuthi ngokoqobo engxenyeni yomzuzwana ukusuka “ephuzwini elinguziro” ama-proton, ama-neutron nama-electron kwakhiwa, okungukuthi, ama-athomu akhona. Ngemva kwemizuzu embalwa (njengoba iNdawo Yonke iphola nokuminyana kwezinto kuncipha), ama-nucleon ahlangana ukuze akhe ama-nuclei ezakhi ngaphandle kwe-hydrogen. Inani elikhulu kakhulu le-helium lakhiqizwa, kanye neminonjana yezinto ezintathu ezilandelayo. Kwaba ngemva kweminyaka eyikhulu kuphela lapho izimo zenza kwaba nokwenzeka ukuhlanganisa ama- electron nama- nuclei—ama-athomu okuqala akheka. Kwadingeka silinde isikhathi eside kwabalandelayo. Ukushintshashintsha okungahleliwe kokuminyana kubangele ukwakheka kokuminyana, okwathi, njengoba kwavela, kwakhanga indaba eyengeziwe. Ngokushesha izinkanyezi zokuqala zavela ebumnyameni be-Universe.
Ngemva kweminyaka engaba yizigidi eziyinkulungwane, abanye babo baqala ukufa. Enkambweni yabo bakhiqiza ama-athomu kuze kufike ensimbini. Manje, njengoba befa, basakaza kuso sonke isifunda, futhi izinkanyezi ezintsha zazalwa emlotheni. Okukhulu kunabo bonke kwaba nesiphetho esimangalisayo. Phakathi nokuqhuma kwe-supernova, ama-nuclei ahlaselwa izinhlayiya eziningi kangangokuthi ngisho nezakhi ezisinda kakhulu zakhiwa. Kusuka kuzo izinkanyezi ezintsha, amaplanethi, nakweminye imbulunga - kwakhiwa ukuphila.
Ukuba khona kwamagagasi ezinto kuye kwafakazelwa. Ngakolunye uhlangothi, i-electron e-athomu yayibhekwa njengegagasi elimile, ngenxa yokuthi alikhiphi amandla. Izakhiwo zamagagasi zama-electron anyakazayo zasetshenziswa ukuze kwakhiwe ama-electron microscopes, okuvumela ama-athomu ukuba abonakale okokuqala ngqa (6). Eminyakeni eyalandela, umsebenzi kaWerner Heisenberg no-Erwin Schrödinger (ngokusekelwe kumbono ka-De Broglie) wavumela ukuthuthukiswa kwemodeli entsha, egcwele amandla yamagobolondo e-electron e-athomu. Kodwa lena imibuzo engaphezu kobubanzi balesi sihloko.
Iphupho lezazi ze-alchem lifezekile
Ukuguqulwa kwemvelo kwe-radioactive, lapho kwakheka izakhi ezintsha, bekwaziwa kusukela ekupheleni kwekhulu le-1919. Ngo-XNUMX, into imvelo kuphela ebikwazi ukuyenza kuze kube manje. Ngalesi sikhathi, u-Ernest Rutherford wafunda ukusebenzisana kwezinhlayiya nendaba. Ngesikhathi sokuhlolwa, waqaphela ukuthi ama-proton avela ngenxa yokushiswa kwegesi ye-nitrogen.
Okuwukuphela kwencazelo yalesi senzakalo kwaba ukusabela phakathi kwe-helium nuclei (i-particle kanye ne-nucleus ye-isotope yalesi sici) ne-nitrogen (7). Ngenxa yalokho, kwakhiwa umoya-mpilo ne-hydrogen (i-proton iyi-nucleus ye-isotope elula kakhulu). Iphupho lezazi ze-alchem of transmutation lifezekile. Emashumini eminyaka alandela, kwakhiqizwa izakhi ezingenzeki emvelweni.
Amalungiselelo emvelo emisebe akhipha izinhlayiya ze-alpha ayengasafaneleki kule njongo (umgoqo we-Coulomb we-nuclei esindayo mkhulu kakhulu ukuba inhlayiya yokukhanya ingasondela kuwo). Ama-accelerator anikeza amandla amakhulu kuma-nuclei ama-isotopes asindayo aphenduka "izithando zomlilo ze-alchemical" lapho okhokho bamakhemikhali banamuhla bazama ukuthola "inkosi yensimbi" (8).
Empeleni, kuthiwani ngegolide? Ama-alchemists avame ukusebenzisa i-mercury njengento eluhlaza ekukhiqizeni kwayo. Kumele kuvunywe ukuthi kulokhu babe "nekhala" langempela. Kwakusuka ku-mercury ephathwe ngama-neutron kureactor yenuzi lapho igolide lokwenziwa latholwa kuqala. Ucezu lwensimbi lwaboniswa ngo-1955 e-Geneva Atomic Conference.
6. Ama-athomu angaphezulu kwegolide, abonakala esithombeni esithwebulayo ngesibonakhulu.
7. Uhlelo lokuguquguquka kokuqala komuntu kwezakhi
Izindaba zokuphumelela kwezazi zefiziksi zaze zabangela isiyaluyalu sesikhashana ekuhwebeni komhlaba, kodwa imibiko yabezindaba evusa amadlingozi yaphikiswa ulwazi olumayelana nentengo yensimbi embiwa ngale ndlela - ibiza izikhathi eziningi kunegolide lemvelo. Ama-reactors ngeke athathe indawo yemayini yensimbi eyigugu. Kodwa ama-isotopes nezakhi zokwenziwa ezikhiqizwa kuzo (ngezinjongo zokwelapha, amandla, ucwaningo lwesayensi) zibaluleke kakhulu kunegolide.
8. I-cyclotron yomlando ehlanganisa izakhi ezimbalwa zokuqala ngemva kwe-uranium kuthebula le-periodic (Lawrence Radiation Laboratory, University of California, Berkeley, August 1939)
Kubafundi abangathanda ukuhlola izindaba eziphakanyiswe embhalweni, ngincoma uchungechunge lwezihloko zikaMnu. Tomasz Sowiński. Ivele kokuthi “Isu Lentsha” ngo-2006-2010 (esigabeni sokuthi “Itholwe kanjani”). Imibhalo iyatholakala nakusizindalwazi sombhali ku:.
Cycle "Nge-athomu kuze kube phakade“Ngaqala ngesikhumbuzo sokuthi ikhulu leminyaka elidlule lalivame ukubizwa ngokuthi inkathi ye-athomu. Vele, umuntu ngeke ehluleke ukuphawula izimpumelelo eziyisisekelo zosolwazi befiziksi nosokhemisi bekhulu lesi-XNUMX ekwakhiweni kwendaba. Nokho, eminyakeni yamuva nje, ulwazi mayelana ne-microworld lukhula ngokushesha futhi ngokushesha, futhi kuthuthukiswa ubuchwepheshe obenza kube nokwenzeka ukusebenzisa ama-athomu nama-molecule ngamanye. Lokhu kusinika ilungelo lokusho ukuthi iminyaka yangempela ye-athomu ayikakafiki.
