Kun san abin da hertz gwaji? Wani bincike ne da masana kimiyya James Franck da Gustav Ludwig Hertz suka gudanar a karon farko a shekara ta 1914, wanda manufarsa ita ce ta tabbatar da kididdige yawan makamashin electrons da ke cikin atom.
Gwajin Franck da Hertz
Gwajin Hertz ya sami damar tabbatar da samfurin kididdigar Bohr na zarra, yana tabbatar da cewa atom ɗin suna iya ɗaukar takamaiman adadin kuzari da ake kira quanta. Don haka, wannan shine ɗayan mahimman gwaje-gwajen kimiyyar lissafi. Don wannan binciken, an ba Franck da Hertz lambar yabo ta Nobel a cikin Physics a 1925.
Tarihi, Wanene Hertz?
A cikin shekara ta 1913, Niels Bohr ya ba da shawarar wanzuwar sabon samfurin atom, wanda daga baya ake kira da. Bohr Atomic Model, kuma ya ba da shawarar wanzuwar lantarki ta kewayawa, wanda ya kasance a matsayin samfurin Rutherford Atomic Model, da yawa kamar tsarin duniya. Da samfurinsa ya ba da shawarar postulates guda huɗu, ɗaya daga cikinsu yana da alaƙa da ƙididdige ra'ayi na orbits na electrons.
Ta wannan hanyar, gwaje-gwajen farko suna da manufar samun damar tabbatar da wannan ƙididdigewa. A gwaje-gwajen farko, an yi amfani da haske, tun da a lokacin an san cewa haske yana da adadin kuzari. A saboda wannan dalili, Bohr yana sukar gaskiyar cewa sakamakon ƙididdigewa na orbits, sabili da haka, na ƙididdige adadin kuzarin makamashi na electrons na atom, sun samo asali ne kawai a cikin ƙididdigar haske.
A cikin 1914, Franck da Hertz, waɗanda ke aiki akan ionization makamashi na atom, sun ƙirƙira wani gwaji ta amfani da matakan makamashi na atom na mercury. Gwajinsa ya yi amfani da electrons da mercury atom, ba tare da amfani da wani haske ba. Bohr don haka ya sami nunin da ba za a iya warware shi ba na ƙirar atomic ɗin sa.
Gwajin Hertz a aikace
Da farko, don nuna ƙididdige matakan makamashi, sun yi amfani da triode, wanda ya ƙunshi cathode, polarized grid da anode, wanda ke da ikon ƙirƙirar katako na lantarki a cikin bututu mai dauke da mercury a cikin yanayin gaseous. .
Daga nan sai suka ci gaba da auna gyare-gyaren na'urar da aka samu ta hanyar anode bisa ga karfin motsin da ke tattare da electrons, ta haka ne suka sami damar gano asarar makamashin da electrons suka yi a lokacin da suka yi karo da juna.
Material
Ƙungiyar triode tana ƙunshe a cikin kwandon gilashi mai ɗauke da mercury. Yana yiwuwa a gudanar da wannan gwaji a yanayin zafi daban-daban kuma yana da mahimmanci a iya kwatanta waɗannan sakamakon tare da ma'auni a cikin zafin jiki, wanda mercury zai kasance a cikin yanayin ruwa.
Lokacin da aka yi zafi da mercury zuwa zafin jiki na 630 K, ya zama gas. Amma don guje wa kaiwa ga wannan zafin jiki, yana yiwuwa a yi aiki tare da rage matsa lamba a cikin capsule kuma ana iya yin zafi zuwa zafin jiki tsakanin 100 zuwa 200 ° C.
Don fitar da electrons kuma don isa ga saurin da ya dace, dole ne a yi amfani da ƙarfin lantarki wanda zai kasance tsakanin cathode da grid, wanda zai zama ƙarfin haɓakawa, yana samarwa. igiyoyin rediyo. Hakazalika, yana iya zama mai ban sha'awa don sanya wutar lantarki a cikin kishiyar shugabanci, tsakanin anode da grid, don rage ƙarfin lantarki.
Sakamakon gwajin Hertz
Kamar yadda bayani a ciki Tarihin rayuwar Hertz, Sakamakon wannan gwaji shi ne cewa zai yiwu a wakilci hanyar da yuwuwar bambancin da zai haifar da mai canzawa na yanzu-voltage wanda aka sanya a cikin fitowar anode ya samo asali, dangane da haɓaka yiwuwar haɓakar haɓakar electrons daga cathode.
Don samun ƙananan bambance-bambance masu yuwuwa, ƙasa zuwa 4,9 V, halin yanzu yana gudana ta cikin bututu yana ƙaruwa akai-akai tare da haɓaka yuwuwar bambanci. Tare da mafi girman ƙarfin wutar lantarki filin lantarki a cikin bututu yana ƙaruwa kuma za a zana electrons tare da ƙarin ƙarfi zuwa grid na hanzari. A wannan yanayin, ana lura da cewa a 4,9 volts, halin yanzu yana raguwa ba zato ba tsammani, kusan komawa sifili.
Nauyin na yanzu zai karu a hankali idan wutar lantarki ta ci gaba da karuwa, har sai an kai 9.8 volts, wanda shine sau biyu daidai adadin farko na yanzu da ake amfani da shi, kuma muna iya ganin cewa kwatsam kwatsam ya faru a 9.8 volts. Wannan jerin faɗuwar yanzu don haɓaka kusan 4.9 volts za su riƙe a bayyane zuwa yuwuwar aƙalla kusan volts 100.
Fassarar sakamakon gwajin Hertz
Franck da Hertz sun sami damar yin bayanin gwaje-gwajen su a ƙarƙashin yanayi na karo na roba da kuma karon na'urorin lantarki. A ƙananan ma'auni, ƙarfin wutar lantarki da aka haɓaka sun sami matsakaicin adadin kuzarin motsa jiki. Lokacin da suka fuskanci atom ɗin mercury a cikin bututun gilashi, sun yi karo ne kawai na roba.
Wannan yana da dalilinsa na kasancewa a cikin hasashen injin ƙididdiga wanda ke nuni da cewa zarra ba zai iya ɗaukar kowane makamashi ba har sai makamashin karon ya zarce ƙimar da ake buƙata don tada wutar lantarki wanda ke daure ya faɗi atom a wani matakin makamashi mafi girma.
Don kawai karo na roba, cikakken adadin kuzarin motsi a cikin tsarin ya kasance iri daya. Saboda electrons suna da ma'aunin nauyi wanda ya fi sautu kusan sau dubu fiye da ƙananan atom ɗin, wannan yana nufin cewa yawancin electrons sun riƙe ƙarfin motsin su, suna zama. hertz taguwar ruwa. Mahimman abubuwan da suka fi girma sun haifar da fitar da ƙarin electrons daga grid zuwa anode kuma sun yi nasara wajen haɓaka halin yanzu, har sai yuwuwar haɓakawa ya kai 4.9 volts.
Mafi ƙarancin kuzarin kuzarin lantarki da zarra na mercury zai iya samun buƙatun 4,9 volts na lantarki (eV). A cikin yanayin da ƙarfin haɓaka ya kai 4.9 volts, kowane electron kyauta ya sha daidai 4.9 eV na makamashin motsa jiki, sama da sauran kuzarinsa a wannan zafin, lokacin da ya isa grid.
Don haka, karo tsakanin zarra na mercury da na’urar lantarki na kyauta na iya zama maras ƙarfi a wancan lokacin, wato makamashin motsa jiki na electron kyauta za a iya juya shi zuwa makamashi mai ƙarfi ta hanyar burge matakin makamashin na’urar lantarki da ke da atom ɗin mercury. . Lokacin da duk ƙarfin motsinsa ya ɓace, electron ɗin kyauta ba zai iya shawo kan ƙaramin mummunan ƙarfin lantarki a ƙasa ba, kuma wutar lantarki tana faɗuwa da sauri.
Lokacin da ƙarfin wutar lantarki ya karu, electrons suna haifar da karo marar ƙarfi, suna rasa ƙarfin motsin su na 4.9 eV, amma sai su kasance a cikin yanayin haɓaka. Ta wannan hanyar, halin yanzu da aka auna yana sake tashi lokacin da ƙarfin haɓaka ya karu, yana farawa daga 4.9 V. Lokacin da aka kai 9.8 V, yanayin ya sake canzawa.
A wannan lokacin, kowane nau'in lantarki yana da makamashin da ya dace don zama wani ɓangare na karo guda biyu na rashin ƙarfi, wanda ke gudanar da motsa jiki na mercury guda biyu, sa'an nan kuma ya rasa dukkanin makamashin su. Wannan shine abin da ke bayyana raguwar abubuwan da aka lura a halin yanzu. A cikin 4.9 volt tazara, wannan hanya za ta maimaita kanta, saboda electrons za su fuskanci wani inelastic karo.
