Umlando Wokutholwa Kwe-Atomic Nucleus
Ukutholakala kwe-nucleus ye-athomu kwakungenye yezenzakalo ezinkulu emlandweni wesayensi, kwaba nomthelela omkhulu ekuqondeni kwethu isakhiwo sezinto. Umlando wayo uhlanganisa izivivinyo eziningi ezibucayi kanye namakhulu eminyaka emicabango yesayensi. Okulandelayo ukubuka ngokujulile ukuthi umqondo we-nucleus ye-athomu watholakala futhi wathuthukiswa kanjani.
Ikhulu le-19: Imvelaphi kanye Nemibono Yokuqala
Ngasekupheleni kwekhulu le-19, umbono we-athomu wawulawulwa yiPlum Pudding Model eyaphakanyiswa nguJ.J. Thomson ngo-1904. Kulo modeli, i-athomu yavezwa njenge-"pudding" eshajeke kahle ene-"raisin" yama-electron asakazeke yonke indawo. UThomson wathola i-electron ngo-1897, okuyinhlayiya yokuqala ye-subatomic eyatholakala. Kodwa-ke, nakuba ukutholwa kwakhe kwakushintsha kakhulu, ama-electron ayedinga ukuhlelwa ngaphakathi kwesakhiwo se-athomu esinemininingwane eminingi.
Ukuhlolwa kweGeiger-Marsden (1909-1911): Iphuzu Elibalulekile Lokuguquka
Ukuhlolwa okubucayi okwaletha ushintsho olukhulu ekuqondeni isakhiwo se-athomu kwaba ukuhlolwa okwaziwa ngokuthi i-Geiger-Marsden Experiment noma i-Gold Decay Experiment, okwenziwa nguHans Geiger no-Ernest Marsden ngaphansi kokuqondiswa kuka-Ernest Rutherford.
Kulolu vivinyo, umsebe wezinhlayiya ze-alpha (izinhlayiya ezishajelwe kahle ezikhishwa yizinto ezikhipha imisebe njenge-radium) wadutshulwa ephepheni elincane le-foil yegolide. Ngokusho kwe-Plum Pudding Model, izinhlayiya kwakufanele zingene ku-foil ngokuphambuka okuncane ngenxa yokusatshalaliswa ngokulinganayo kweshaja. Kodwa-ke, imiphumela ibonise into ehluke kakhulu: ngenkathi iningi lezinhlayiya ze-alpha lingene ku-foil njengoba bekulindelekile, inani elincane lezinhlayiya lagxuma ngama-engeli amakhulu kakhulu, ezinye zaze zagxuma zaya emthonjeni.
Imodeli Ye-Atomic KaRutherford (1911): I-Atomic Nucleus Yokuqala
URutherford waphetha ngokuthi iPlum Pudding Model yayingenakukwazi ukuchaza lesi simo. Ngakho-ke, waphakamisa imodeli entsha ye-athomu eyaziwa ngokuthi iRutherford Model noma iRutherford Solar System Model ngo-1911. Kulo modeli, i-athomu yakhiwa yi-nucleus encane, eqinile kakhulu, ene-positive charged enkabeni yayo, futhi ama-electron ahambahamba kule nucleus, efana namaplanethi azungeza ilanga.
URutherford wabonisa ukuthi i-nucleus kumele ibe yincane kakhulu uma kuqhathaniswa nosayizi ophelele we-athomu. Nakuba lo modeli uphumelele kakhulu ekuchazeni imiphumela yokuhlolwa kokubola kwegolide, wawunobuthakathaka, ikakhulukazi maqondana nokuzinza kwama-electron azungeza i-nucleus, okwakucatshangwa ukuthi angase awele ku-nucleus ngenxa yemisebe kagesi ekhishwayo.
Intuthuko Eqhubekayo: Imodeli Ye-Atomic kaBohr (1913)
Eminyakeni emibili ngemva kokuba uRutherford ethule imodeli yakhe yenuzi, uNiels Bohr, isazi sesayensi yefilosofi saseDenmark, wandisa imodeli ye-athomu kaRutherford ngokwethula i-quantum mechanics. UBohr waphakamisa ukuthi ama-electron ahambe ngemijikelezo engaguquki, ehlukene ezungeze i-nucleus, nokuthi amandla ama-electron angashintsha kuphela ngokugxuma kwe-quantum phakathi kwalezi zijikelezo. Imodeli kaBohr yayibalulekile ekuchazeni i-hydrogen line spectrum, imodeli kaRutherford eyayingenakuyichaza.
Ukucebisa Umqondo Oyinhloko: Ukutholakala Kwama-Proton Nama-Neutron
Nakuba uRutherford ayephakamise ukuthi kukhona i-nucleus enkabeni ye-athomu, isithombe esiphelele sokwakheka kwe-nucleus sasingakacaciswa ngokugcwele. Ngo-1918, uRutherford wafakazela ngokuhlola ukuthi kukhona ama-proton—izinhlayiya ezishaje kahle ku-nucleus ye-athomu—ngokuhlola kwakhe nge-nitrogen.
Nokho, i-nucleus ye-athomu ayinakwakhiwa ngama-proton kuphela ngoba isisindo se-nucleus sikhulu kunesamba sesisindo sama-proton angaphakathi kwayo. Lokhu kwaholela ekuqageleni ukuthi kwakukhona ezinye izinhlayiya ku-nucleus. Ngo-1932, uJames Chadwick wathola i-neutron, inhlayiya engathathi hlangothi enesisindo esicishe sifane ne-proton, eyasiza ekuchazeni isisindo esengeziwe se-nucleus ye-athomu.
Ukutholakala Okwengeziwe Kwe-Isotopes Nesakhiwo Senuzi
Ngokutholakala kwama-proton nama-neutron, kwavela umqondo wama-isotopes. Ama-Isotopes ayizinhlobo zesakhi samakhemikhali esinenani elifanayo lama-proton kodwa izinombolo ezahlukene zama-neutron kuma-nuclei awo e-athomu. Lokhu kuchaza ukuthi kungani isakhi samakhemikhali esifanayo singaba nobuningi be-athomu obuhlukene.
Ucwaningo olwengeziwe lwesakhiwo senuzi luveze nokuba khona kwamandla enuzi aqinile, amandla agcina ama-proton nama-neutron ndawonye ku-nucleus naphezu kokuxoshwa kwe-electromagnetic phakathi kwama-proton.
Umphumela Wokutholakala Kwe-Atomic Nucleus
Ukutholakala kwe-nucleus ye-athomu akuchazanga nje kuphela isakhiwo se-athomu kodwa futhi kwavula indlela yokuthuthukiswa kwe-physics ye-nuclear kanye ne-chemistry yesimanje. Ukuqonda i-nucleus kwavumela ukusungulwa kobuchwepheshe obufana ne-reactor yenuzi kanye nebhomu le-athomu. Amasu okuthwebula izithombe zezokwelapha njenge-Positron Emission Tomography (PET) kanye ne-Magnetic Resonance Imaging (MRI) nawo asekelwe olwazini lokuziphatha kwama-athomu kanye nezinhlayiya ezincane ze-athomu.
Ucwaningo nge-nucleus ye-athomu luphinde lwaba negalelo elikhulu ekusetshenzisweni kwe-quantum mechanics kanye nemodeli ejwayelekile yezinhlayiya ezihilela ama-quark, ama-gluon, kanye nokusebenzisana kwenuzi. Le mpumelelo ibonisa ukubaluleka kokutholakala kwe-nucleus ye-athomu ekuthuthukisweni kwesayensi.
Isiphetho
Ukutholakala kwe-nucleus ye-athomu kanye nemibono eyizungezile kushintshe ubuso be-physics kanye ne-chemistry, kwanikeza ukuqonda okuyisisekelo kwendaba eyakha indawo yonke. Kusukela ku-Plum Pudding Model ka-J.J. Thomson kuya ekuhlolweni kukaGeiger-Marsden kanye nokutholakala kwe-nucleus kukaRutherford, kanye nentuthuko eyengeziwe yososayensi abanjengoBohr noChadwick, uhambo lokuthola lubonisa intuthuko yesayensi ngokubambisana, ukuhlola, kanye nokuzinikela okungapheli ekuqondeni umhlaba osizungezile. Lokhu okutholiwe akugcini nje ngokucebisa isayensi kodwa futhi kuguqule ubuchwepheshe kanye nokuphila kwabantu ngokuyisisekelo.
