Tare da zarra ta tsawon shekaru - part 3

Tsarin duniyar Rutherford na zarra ya fi kusa da gaskiya fiye da "raisin pudding" na Thomson. Duk da haka, rayuwar wannan ra'ayi ya kasance kawai shekaru biyu, amma kafin magana game da magaji, lokaci ya yi da za a bayyana asirin atomic na gaba.

1. Hydrogen isotopes: barga prot da deuterium da radioactive tritium (hoto: BruceBlaus/Wikimedia Commons).

bala'in nukiliya

Gano abin da ya faru na rediyoactivity, wanda ya nuna farkon bayyanar da asirai na zarra, da farko ya yi barazana ga tushen ilmin sunadarai - ka'idar lokaci-lokaci. A cikin ɗan gajeren lokaci, an gano abubuwa da yawa na rediyoaktif. Wasu daga cikinsu suna da sinadarai iri ɗaya, duk da nau'in atomic ɗin daban-daban, yayin da wasu kuma tare da talakawa iri ɗaya, suna da halaye daban-daban. Haka kuma, a fannin tebur na lokaci-lokaci inda yakamata a sanya su saboda nauyinsu, babu isasshen sarari kyauta don ɗaukar su duka. An yi asarar tebur na lokaci-lokaci saboda yawan abubuwan da aka gano.

2. Kwafi na J.J. Thompson's 1911 mass spectrometer (hoto: Jeff Dahl/Wikimedia Commons)

atomic tsakiya

Wannan shi ne 10-100 dubu. sau ƙanƙanta fiye da dukan zarra. Idan za a fadada tsakiya na atom na hydrogen zuwa girman ball mai diamita na 1 cm kuma a sanya shi a tsakiyar filin wasan kwallon kafa, to electron (ƙananan fiye da fiɗa) zai kasance a kusa da manufa. (fiye da 50 m).

Kusan dukkanin adadin zarra yana tattara a cikin tsakiya, alal misali, na zinariya kusan 99,98%. Ka yi tunanin cube na wannan ƙarfe yana yin nauyin ton 19,3. Duka nuclei na atom zinari yana da jimlar ƙarar ƙasa da 1/1000 mm3 (ball mai diamita na ƙasa da 0,1 mm). Saboda haka, zarra ba komai bane. Dole ne masu karatu su ƙididdige yawan abubuwan tushe.

An samo maganin wannan matsala a cikin 1910 na Frederick Soddy. Ya gabatar da manufar isotopes, watau. nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in atomic (1). Don haka, ya yi tambaya game da wani matsayi na Dalton - tun daga wannan lokacin, sinadarin sinadari bai kamata ya kasance ya ƙunshi atom ɗin ma'auni ɗaya ba. Hasashen isotopic, bayan tabbatar da gwaji (mass spectrograph, 1911), kuma ya ba da damar yin bayani kan ƙimar juzu'i na ma'aunin atomic na wasu abubuwan - yawancinsu gaurayawan isotopes da yawa ne, kuma atomic taro shi ne ma'aunin nauyi na talakawan su duka (2).

Abubuwan Kernel

Wani daga cikin ɗaliban Rutherford, Henry Moseley, ya yi nazarin X-ray da sanannun abubuwa ke fitarwa a shekara ta 1913. Ba kamar hadaddun na'urar gani da ido ba, bakan X-ray yana da sauqi qwarai - kowane nau'in sinadari yana fitar da tsayin raƙuman ruwa guda biyu ne kawai, wanda tsawonsa yana da alaƙa cikin sauƙi tare da cajin tsakiya na atomic.

3. Daya daga cikin injinan X-ray da Moseley ke amfani da shi (hoto: Magnus Manske/Wikimedia Commons)

Wannan ya sa a karon farko aka gabatar da ainihin adadin abubuwan da ake da su, da kuma tantance nawa ne har yanzu ba su isa su cike gibin da ke cikin tebur na lokaci-lokaci (3).

Barbashi da ke ɗauke da tabbataccen caji ana kiransa proton (Proton na Girka = farko). Nan take wata matsala ta taso. Yawan proton yana kusan daidai da raka'a 1. Alhali atomic tsakiya sodium tare da cajin raka'a 11 yana da adadin raka'a 23? Hakanan, ba shakka, shine yanayin sauran abubuwan. Wannan yana nufin cewa dole ne a sami wasu barbashi da ke cikin tsakiya kuma ba tare da caji ba. Da farko, masana kimiyya sun ɗauka cewa waɗannan protons ne masu ƙarfi da aka daure da electrons, amma a ƙarshe an tabbatar da cewa wani sabon barbashi ya bayyana - neutron (Latin neuter = tsaka tsaki). Gano wannan ɓangarorin farko (abin da ake kira “tubalin” na asali waɗanda ke tattare da komai) an yi shi ne a cikin 1932 na masanin kimiyyar ɗan ƙasar Ingila James Chadwick.

Protons da neutrons na iya juya juna. Masana kimiyya sun yi hasashen cewa su nau'i ne na wani barbashi da ake kira nucleon (Latin nucleus = nucleus).

Tunda tsakiya na isotope mafi sauƙi na hydrogen shine proton, ana iya ganin William Prout a cikin hasashe na "hydrogen". atomic yi bai yi kuskure da yawa ba (duba: "Tare da zarra ta cikin shekaru - sashi na 2"; "Masanin Fasaha" No. 8/2015). Da farko, an sami ma sauyi tsakanin sunayen proton da “proton”.

4. Photocells a ƙarshe - tushen aikin su shine tasirin photoelectric (hoto: Ies / Wikimedia Commons)

Ba a yarda da komai ba

Misalin Rutherford a lokacin bayyanarsa yana da “laifi na haihuwa”. Bisa ga dokokin Maxwell na electrodynamics (wanda aka tabbatar ta hanyar watsa shirye-shiryen rediyo da ke aiki a wancan lokacin), lantarki mai motsi a cikin da'irar ya kamata ya haskaka igiyoyin lantarki.

Don haka, yana rasa kuzari, sakamakon abin da ya fada kan tsakiya. A ƙarƙashin yanayin al'ada, ƙwayoyin zarra ba sa haskakawa (ana yin sikirin idan aka yi zafi zuwa yanayin zafi mai zafi) kuma ba a lura da bala'in atomic (ƙididdigar rayuwar wutar lantarki ya kai ƙasa da miliyan ɗaya na daƙiƙa).

Misalin Rutherford ya bayyana sakamakon gwajin watsewar barbashi, amma har yanzu bai dace da gaskiya ba.

A cikin 1913, mutane sun "yi amfani" don gaskiyar cewa ana ɗaukar makamashi a cikin microcosm kuma an aika ba a kowane adadi ba, amma a cikin sassan da ake kira quanta. A kan haka ne Max Planck ya yi bayanin yanayin bakan radiation da masu zafi ke fitarwa (1900), kuma Albert Einstein (1905) ya yi bayanin sirrin tasirin photoelectric, watau fitar da electrons ta hanyar hasken karafa (4).

5. Hoton rarrabuwar kawuna na electrons akan kristal tantalum oxide yana nuna madaidaicin tsarin sa (hoto: Sven.hovmoeller/Wikimedia Commons)

Wani masanin kimiyya dan kasar Denmark Niels Bohr dan shekara 28 ya inganta tsarin atom na Rutherford. Ya ba da shawarar cewa electrons suna motsawa ne kawai a cikin kewayawa da suka dace da wasu yanayi na makamashi. Bugu da ƙari, electrons ba sa fitar da radiation yayin da suke motsawa, kuma makamashi yana shiga kuma yana fitowa ne kawai lokacin da aka kunna tsakanin kewayawa. Zato ya ci karo da ilmin kimiyyar lissafi na gargajiya, amma sakamakon da aka samu a kan tushensu (girman atom na hydrogen da tsawon layin bakansa) ya zama daidai da gwajin. sabon haihuwa model atom.

Abin takaici, sakamakon yana aiki ne kawai don zarra na hydrogen (amma bai bayyana duk abubuwan lura ba). Ga wasu abubuwa, sakamakon lissafin bai dace da gaskiya ba. Don haka, masana kimiyya har yanzu ba su sami samfurin ka'idar atom ba.

Asirin ya fara bayyana bayan shekaru goma sha ɗaya. Likitan digiri na masanin kimiyyar lissafi na Faransa Ludwik de Broglie ya yi magana game da kaddarorin ɓangarorin abu. An riga an tabbatar da cewa haske, ban da halaye na hali na igiyar ruwa (diffraction, refraction), kuma yana aiki kamar tarin barbashi - photons (misali, karo na roba tare da electrons). Amma manyan abubuwa? Shawarar ta zama kamar mafarki mai ban tsoro ga wani yarima mai son zama masanin kimiyyar lissafi. Duk da haka, a cikin 1927 an gudanar da wani gwaji wanda ya tabbatar da hasashe na de Broglie - katako na lantarki ya rarraba akan wani karfe (5).

A ina ne kwayoyin zarra suka fito?

Kamar kowa: Big Bang. Masana kimiyyar lissafi sun yi imanin cewa a zahiri a cikin juzu'in daƙiƙa guda daga "sifili point" protons, neutrons da electrons, wato, kwayoyin halitta, an samu su. Bayan 'yan mintoci kaɗan (lokacin da sararin samaniya ya yi sanyi, kuma yawan kwayoyin halitta ya ragu), nucleons sun haɗu tare, sun zama ƙwararrun abubuwan da ba hydrogen ba. An samar da mafi girman adadin helium, da kuma alamun abubuwa guda uku masu zuwa. Sai kawai bayan 100 XNUMX Shekaru da yawa, yanayi ya ba da damar electrons su ɗaure ga nuclei - an samo asali na farko. Sai da na dade na jira na gaba. Canje-canje na bazuwar a cikin yawa ya haifar da samuwar yawa, wanda, kamar yadda suka bayyana, ya jawo hankalin kwayoyin halitta. Ba da daɗewa ba, a cikin duhun sararin samaniya, taurari na farko sun haskaka.

Bayan kimanin shekaru biliyan, wasu daga cikinsu sun fara mutuwa. A cikin tafarkinsu sun samar nuclei na atom ƙasa da baƙin ƙarfe. Sa'ad da suka mutu, suka bazu ko'ina cikin yankin, aka haifi sababbin taurari daga cikin toka. Mafi girman su yana da kyakkyawan ƙarshe. A lokacin fashe-fashen supernova, an yi ruwan bama-bamai da kwayoyin halitta da yawa wanda har ma an samu wasu abubuwa masu nauyi. Sun kafa sababbin taurari, taurari, kuma a kan wasu duniyoyi - rayuwa.

An tabbatar da kasancewar igiyoyin kwayoyin halitta. A daya bangaren kuma, ana daukar na’urar lantarki a cikin zarra a matsayin igiyar igiyar ruwa, wanda a dalilinsa ba ya hasko makamashi. An yi amfani da kaddarorin motsi na electrons don ƙirƙirar microscopes na lantarki, wanda ya ba da damar ganin atom a karon farko (6). A cikin shekaru masu zuwa, aikin Werner Heisenberg da Erwin Schrödinger (a kan tushen de Broglie hypothesis) ya sa ya yiwu a samar da sabon samfurin na'urorin lantarki na atom, gaba daya bisa kwarewa. Amma waɗannan tambayoyi ne da suka wuce iyakar labarin.

Mafarkin malaman alchem ​​ya cika

Canje-canje na rediyoaktif na dabi'a, wanda a ciki aka samar da sabbin abubuwa, an san su tun ƙarshen ƙarni na 1919. A cikin XNUMX, wani abu wanda kawai yanayi ya iya har yanzu. Ernest Rutherford a wannan lokacin ya tsunduma cikin hulɗar barbashi da kwayoyin halitta. A lokacin gwaje-gwajen, ya lura cewa protons sun bayyana a sakamakon hasken wuta da iskar nitrogen.

Iyakar bayanin abin da ya faru shine dauki tsakanin helium nuclei (barbashi da tsakiya na isotope na wannan sinadari) da nitrogen (7). A sakamakon haka, oxygen da hydrogen suna samuwa (proton shine tsakiya na isotope mafi sauƙi). Mafarkin alchemists na canzawa ya zama gaskiya. A cikin shekaru masu zuwa, an samar da abubuwan da ba a samo su a cikin yanayi ba.

Shirye-shiryen rediyoaktif na dabi'a masu fitar da a-barbashi ba su dace da wannan dalili ba (shamakin Coulomb na tsakiya masu nauyi ya yi girma don barbashi mai haske ya kusanci su). Accelerators, ba da babbar makamashi ga tsakiya na nauyi isotopes, ya zama "alchemical tanderu" a cikinsa kakannin chemists a yau kokarin samun "sarkin karafa" (8).

A gaskiya, zinariya fa? Alchemists galibi suna amfani da mercury azaman ɗanyen abu don samar da shi. Dole ne a yarda cewa a cikin wannan yanayin suna da "hanci" na gaske. Daga mercury da aka yi da neutron a cikin injin nukiliya ne aka fara samun zinare na wucin gadi. An nuna guntun karfe a cikin 1955 a taron Atomic na Geneva.

Hoto 6. Atom a saman gwal, wanda ake iya gani a cikin hoton a cikin na'urar hangen nesa na leken asiri.

7. Tsari na farkon ɗan adam canza abubuwa

Labarin nasarar da masana kimiyya suka yi har ya haifar da wani ɗan gajeren lokaci a kan musayar hannayen jari na duniya, amma rahotanni masu ban sha'awa na manema labaru sun karyata ta hanyar bayanai game da farashin ma'adinan da aka haƙa ta wannan hanya - ya ninka zinariya sau da yawa. Reactors ba za su maye gurbin ma'adinan ƙarfe mai daraja ba. Amma isotopes da abubuwa na wucin gadi da aka samar a cikin su (don dalilai na magani, makamashi, binciken kimiyya) sun fi zinariya daraja sosai.

8. Cyclotron na tarihi yana haɗa abubuwa na farko bayan uranium a cikin tebur na lokaci-lokaci (Lawrence Radiation Laboratory, Jami'ar California, Berkeley, Agusta 1939)

Ga masu karatu waɗanda ke son bincika batutuwan da aka taso a cikin rubutu, Ina ba da shawarar jerin kasidu na Mista Tomasz Sowiński. Ya bayyana a cikin "Young Technics" a cikin 2006-2010 (a ƙarƙashin taken "Yadda suka gano"). Hakanan ana samun rubutun akan gidan yanar gizon marubucin a: .

Zagaye"Tare da zarra har abada» Ya fara da tunatarwa cewa karnin da ya gabata ana kiransa da shekarun atom. Tabbas, mutum ba zai iya kasa yin la'akari da mahimman nasarorin masana kimiyya da masana kimiyya na karni na XNUMX a cikin tsarin kwayoyin halitta ba. Koyaya, a cikin 'yan shekarun nan, ilimin game da ƙananan ƙwayoyin cuta yana haɓaka da sauri da sauri, ana haɓaka fasahohin da ke ba da izinin sarrafa kwayoyin halitta da ƙwayoyin cuta. Wannan ya ba mu 'yancin cewa ainihin shekarun zarra bai isa ba tukuna.