Me kahi atom i nā makahiki - ʻāpana 3

ʻOi aku ka kokoke loa o ke ʻano honua honua a Rutherford i ka ʻātoma ma mua o ka "pudding raisin" a Thomson. Eia nō naʻe, ʻelua makahiki wale nō ka lōʻihi o ke ola o kēia manaʻo, akā ma mua o ka kamaʻilio ʻana e pili ana i kahi hope, ʻo ia ka manawa e wehe ai i nā mea huna atomika e hiki mai ana.

1. Hydrogen isotopes: stable prot and deuterium and radioactive tritium (kiʻi: BruceBlaus/Wikimedia Commons).

nuclear avalanche

ʻO ka loaʻa ʻana o ke ʻano o ka radioactivity, ka mea i hōʻailona i ka hoʻomaka ʻana o ka wehe ʻana i nā mea pohihihi o ka atom, ua hoʻoweliweli mua i ke kumu o ke kemika - ke kānāwai o ka periodicity. I ka manawa pōkole, ua ʻike ʻia kekahi mau kakini radioactive. ʻO kekahi o lākou he mau waiwai kemika like, ʻoiai ka nui o ka atomic like ʻole, a ʻo nā mea ʻē aʻe, me nā nui like, he ʻokoʻa nā waiwai. Eia kekahi, ma kahi o ka papa ʻaina kahi i kau ʻia ai lākou ma muli o ko lākou paona, ʻaʻole lawa ka wahi kaʻawale e hoʻokipa ai iā lākou āpau. Ua nalowale ka papa ʻaina ma muli o ka nui o nā mea i ʻike ʻia.

2. He kope o J.J. Thompson i ka makahiki 1911 mass spectrometer (kiʻi: Jeff Dahl/Wikimedia Commons)

nucleus atomika

ʻO 10-100 tausani kēia. ʻoi aku ka liʻiliʻi ma mua o ka atom holoʻokoʻa. Inā e hoʻonui ʻia ka nucleus o ka hydrogen atom i ka nui o ka pōpō me ke anawaena o 1 knm a hoʻokomo ʻia i waenakonu o kahi kahua pōpeku, a laila aia kahi electron (ʻoi aku ka liʻiliʻi ma mua o ke poʻo pine) ma kahi kokoke i kahi pahuhopu. (ma luna o 50 m).

Kokoke ka nuipa a pau o ka atom i ka nucleus, no ka laʻana, no ke gula ua aneane 99,98%. E noʻonoʻo i kahi pahu o kēia metala he 19,3 mau tona. ʻO nā mea a pau nuclei of atoms ke gula ka huina nui o lalo o 1/1000 mm3 (he poepoe me ke anawaena o emi malalo o 0,1 mm). No laila, nele loa ka atom. Pono nā mea heluhelu e helu i ka mānoanoa o ka mea kumu.

Ua loaʻa ka hopena i kēia pilikia ma 1910 e Frederick Soddy. Ua hoʻolauna ʻo ia i ka manaʻo o nā isotopes, ʻo ia hoʻi. nā ʻano like ʻole o ka mea like ʻokoʻa i ko lākou nui atomika (1). No laila, ua nīnau ʻo ia i kekahi postulate o Dalton - mai ia manawa mai, ʻaʻole pono e hoʻokomo hou ʻia kahi mea kemika i nā ʻātoma o ka nui like. ʻO ke kuhiakau isotopic, ma hope o ka hōʻoia ʻana i ka hoʻokolohua (mass spectrograph, 1911), hiki ke wehewehe i nā waiwai hakina o ka nui atomic o kekahi mau mea - ʻo ka hapa nui o lākou he hui ʻana o nā isotopes he nui, a nuipa atomika 'o ia ka 'awelika kaumaha o ka nui o ia mau mea a pau (2).

Nā mea Kernel

ʻO kekahi haumāna ʻē aʻe o Rutherford, ʻo Henry Moseley, i ka makahiki 1913 i aʻo i nā hihi X i hoʻopuka ʻia e nā mea ʻike. ʻAʻole like me ka spectra optical paʻakikī, he maʻalahi loa ka spectrum X-ray - hoʻopuka kēlā me kēia mea i ʻelua mau nalu nalu wale nō, ʻo ka lōʻihi o ka hawewe e hoʻopili maʻalahi me ka hoʻopiʻi o kāna nucleus atomic.

3. ʻO kekahi o nā mīkini X-ray i hoʻohana ʻia e Moseley (kiʻi: Magnus Manske/Wikimedia Commons)

ʻO kēia ka mea i hiki ai i ka manawa mua ke hōʻike i ka helu maoli o nā mea e noho nei, a me ka hoʻoholo ʻana i ka nui o lākou ʻaʻole lawa e hoʻopiha i nā hakahaka o ka papaʻaina (3).

Ua kapa ʻia kahi ʻāpana e lawe ana i ka hoʻopiʻi maikaʻi he proton (Greek proton = mua). Ua ala koke mai kekahi pilikia. Ua like ka nuipa o ka proton me 1 wae. Oiai nucleus atomika ʻO ka sodium me ka uku o 11 mau ʻāpana he 23 ʻāpana? ʻO ka mea like, ʻoiaʻiʻo, ka hihia me nā mea ʻē aʻe. 'O ia ho'i, pono e loa'a kekahi mau mea 'ē a'e i loko o ka nucleus a 'a'ohe kumu. I ka hoʻomaka ʻana, ua manaʻo nā physicists ua paʻa ikaika kēia mau protons me nā electrons, akā i ka hopena ua hōʻike ʻia ua ʻike ʻia kahi mea hou - ka neutron (Latin neuter = neutral). ʻO ka loaʻa ʻana o kēia ʻāpana haʻahaʻa (ʻo ka mea i kapa ʻia ʻo "bricks" kumu i hana i nā mea āpau) i hana ʻia i ka makahiki 1932 e ka physicist Pelekane ʻo James Chadwick.

Hiki i nā protons a me nā neutrons ke huli i kekahi i kekahi. Manaʻo ka poʻe physicists he mau ʻano ia o kahi ʻāpana i kapa ʻia he nucleon (Latin nucleus = nucleus).

No ka mea he proton ka nucleus o ka isotope hydrogen ma'alahi, hiki ke ike ia William Prout ma kona kuhiakau "hydrogen" hana ʻātoma ʻAʻole hewa loa ʻo ia (e ʻike: "Me ka atom ma o nā makahiki - ʻāpana 2"; "Young Technician" No. 8/2015). I ka wā mua, aia nā loli ma waena o nā inoa proton a me "proton".

4. Nā kiʻi paʻi kiʻi ma ka pau ʻana - ʻo ke kumu o kā lākou hana ka hopena photoelectric (kiʻi: Ies / Wikimedia Commons)

ʻAʻole ʻae ʻia nā mea a pau

ʻO ke kumu hoʻohālike o Rutherford i ka manawa i ʻike ʻia he "congenital defect". Wahi a nā kānāwai electrodynamics o Maxwell (i hōʻoia ʻia e ka hoʻolaha lekiō e hana ana i kēlā manawa), pono e hoʻomālamalama ka electron e neʻe ana i ka pōʻai i kahi nalu electromagnetic.

No laila, nalowale ka ikehu, a ma muli o kona hāʻule ʻana i ka nucleus. Ma lalo o nā kūlana maʻamau, ʻaʻole e hoʻomālamalama nā atoms (ua hoʻokumu ʻia ka spectra i ka wā i wela ai i nā wela kiʻekiʻe) a ʻaʻole i ʻike ʻia nā pōʻino atomic (ʻo ke ola i manaʻo ʻia o ka electron aia ma lalo o hoʻokahi miliona miliona o ke kekona).

Ua wehewehe ke kumu hoʻohālike a Rutherford i ka hopena o ka hoʻāʻo ʻana i ka hoʻoheheʻe ʻana i nā ʻāpana, akā ʻaʻole naʻe i kūlike me ka ʻoiaʻiʻo.

I ka makahiki 1913, ua "hoʻohana" ka poʻe i ka ʻoiaʻiʻo e lawe ʻia ka ikehu i ka microcosm a ʻaʻole i hoʻouna ʻia i kekahi nui, akā i nā ʻāpana, i kapa ʻia ʻo quanta. Ma kēia kumu, wehewehe ʻo Max Planck i ke ʻano o ka spectra o ka radiation emitted e nā kino wela (1900), a wehewehe ʻo Albert Einstein (1905) i nā mea huna o ka hopena photoelectric, ʻo ia hoʻi, ka hoʻokuʻu ʻana o nā electrons e nā metala i hoʻomālamalama ʻia (4).

5. Hōʻike ʻia ke kiʻi ʻokoʻa o nā electrons ma kahi aniani o ka tantalum oxide i kona ʻano like (kiʻi: Sven.hovmoeller/Wikimedia Commons)

Ua hoʻomaikaʻi ʻo Niels Bohr, physicist Denemaka, 28 makahiki, i ke kumu hoʻohālike a Rutherford o ka atom. Ua manaʻo ʻo ia e neʻe nā electrons i nā orbits e kū ana i kekahi mau kūlana ikehu. Eia kekahi, ʻaʻole e hoʻokuʻu nā electrons i ka pāhawewe i ko lākou neʻe ʻana, a hoʻopaʻa ʻia ka ikehu a hoʻokuʻu wale ʻia i ka wā e pale ʻia ma waena o nā orbit. Ua kū'ē nā manaʻo i ka physics kahiko, akā ʻo nā hopena i loaʻa ma ko lākou kumu (ka nui o ka hydrogen atom a me ka lōʻihi o nā laina o kāna kikoʻī) ua kūlike me ka hoʻokolohua. hānau hou model atomu.

ʻO ka mea pōʻino, ua kūpono nā hopena no ka hydrogen atom wale nō (akā ʻaʻole i wehewehe i nā ʻike spectral āpau). No nā mea ʻē aʻe, ʻaʻole i kūlike nā hopena helu me ka ʻoiaʻiʻo. No laila, ʻaʻole i loaʻa i ka poʻe physicist kahi kumu hoʻohālike o ka atom.

Ua hoʻomaka ʻia nā mea pohihihi ma hope o ʻumikumamākahi makahiki. ʻO ka palapala kauka kauka a ka mea physicist Farani ʻo Ludwik de Broglie i hana i nā ʻano nalu o nā mea waiwai. Ua hōʻike mua ʻia ʻo ka māmā, ma kahi o nā ʻano maʻamau o ka nalu (diffraction, refraction), e like me ka hōʻiliʻili o nā ʻāpana - photons (no ka laʻana, elastic collisions me nā electrons). Akā, nā mea nui? Ua like ka manaʻo me he moe paipu lā no kahi aliʻi i makemake e lilo i physicist. Eia nō naʻe, i ka makahiki 1927 ua hoʻokō ʻia kahi hoʻokolohua e hōʻoiaʻiʻo ana i ke kuhiakau o de Broglie - ʻokoʻa ka kukuna electron ma ke aniani metala (5).

No hea mai nā ʻātoma?

E like me nā mea ʻē aʻe: Big Bang. Manaʻo ka poʻe physicists i loko o kahi hapa o ke kekona mai ka protons "zero point", ua hoʻokumu ʻia nā neutrons a me nā electrons, ʻo ia hoʻi, nā atoms constituent. He mau minuke ma hope mai (i ka wā i maʻalili ai ke ao holoʻokoʻa a ua emi ka mānoanoa o ka mea), ua hui pū nā nucleons, a lilo i nuclei o nā mea ʻē aʻe ma waho o ka hydrogen. Ua hoʻokumu ʻia ka nui o ka helium, a me nā ʻāpana o nā mea ʻekolu. Ma hope o 100 XNUMX No nā makahiki he nui, ua ʻae nā kūlana i nā electrons e hoʻopaʻa i ka nuclei - ua hoʻokumu ʻia nā atoms mua. Pono wau e kali lōʻihi no ka mea e hiki mai ana. ʻO ka hoʻololi ʻana i ka density ke kumu o ka hoʻokumu ʻana o nā density, ʻoiai lākou i ʻike ʻia ai, ua huki hou aʻe i nā mea. ʻAʻole koke, i loko o ka pōʻeleʻele o ke ao holoʻokoʻa, ua ʻā nā hōkū mua.

Ma hope o hoʻokahi piliona makahiki, hoʻomaka kekahi o lākou e make. I kā lākou papa hana lākou nuclei of atoms iho i ka hao. I kēia manawa, i ko lākou make ʻana, hoʻolaha lākou iā lākou a puni ka ʻāina, a hānau ʻia nā hōkū hou mai ka lehu. ʻO ka mea nui loa o lākou he hopena kupaianaha. I ka wā o nā pahū supernova, ua hoʻopaʻa ʻia ka nuclei me nā ʻāpana he nui a hiki i nā mea kaumaha loa i hana ʻia. Ua hoʻokumu lākou i nā hōkū hou, nā hōkūhele, a ma kekahi poʻe honua - ke ola.

Ua hōʻoia ʻia ke ola ʻana o nā nalu mea. Ma ka ʻaoʻao ʻē aʻe, ua manaʻo ʻia kahi electron i loko o kahi atom he nalu kū, no laila ʻaʻole ia e hoʻomālamalama i ka ikehu. Ua hoʻohana ʻia nā ʻano hawewe o nā electrons neʻe e hana i nā microscopes electron, i hiki ai ke ʻike i nā ʻātoma no ka manawa mua (6). I nā makahiki ma hope mai, ua hiki i ka hana a Werner Heisenberg lāua ʻo Erwin Schrödinger (ma ke kumu o ka hypothesis de Broglie) ke hoʻomohala i kahi kumu hoʻohālike hou o nā pūpū electron o ka atom, e pili ana i ka ʻike. Akā, he mau nīnau kēia ma waho o ke kiko o ka ʻatikala.

Ua hoʻokō ʻia ka moeʻuhane o ka poʻe alchemist

ʻO nā hoʻololi radioactive kūlohelohe, kahi i hoʻokumu ʻia ai nā mea hou, ua ʻike ʻia mai ka hopena o ke kenekulia 1919. I ka XNUMX, kahi mea i hiki i ke kūlohelohe a hiki i kēia manawa. Ua hana ʻo Ernest Rutherford i kēia wā i ka launa pū ʻana o nā mea ʻāpana me ka mea. I ka wā o nā hoʻāʻo, ʻike ʻo ia ua ʻike ʻia nā protons ma muli o ka irradiation me ke kinoea nitrogen.

ʻO ka wehewehe wale ʻana no kēia mea ʻo ia ka hopena ma waena o ka nuclei helium (kahi ʻāpana a me ka nucleus o kahi isotope o kēia mea) a me ka nitrogen (7). ʻO ka hopena, ua hoʻokumu ʻia ka oxygen a me ka hydrogen (ʻo ka proton ka nucleus o ka isotope māmā loa). Ua hoʻokō ʻia ka moeʻuhane o ka poʻe alchemist no ka transmutation. I nā makahiki i hala iho nei, ua hana ʻia nā mea i ʻike ʻole ʻia ma ke ʻano.

ʻAʻole kūpono nā mea hoʻomākaukau radioactive kūlohelohe no kēia kumu (ua nui loa ka pale Coulomb o nā nuclei kaumaha no kahi ʻāpana māmā e hoʻokokoke iā lākou). ʻO nā accelerators, e hāʻawi ana i ka ikehu nui i ka nuclei o nā isotopes kaumaha, ua lilo ia i "nā kapuahi alchemical", kahi i hoʻāʻo ai nā kūpuna o nā mea kemika o kēia lā e kiʻi i ka "ke aliʻi o nā metala" (8).

ʻOiaʻiʻo, pehea ke gula? Hoʻohana pinepine ka poʻe Alchemist i ka mercury ma ke ʻano he mea maka no kāna hana. Pono e ʻae ʻia i kēia hihia he "ihu" maoli ko lākou. Mai ka mercury i mālama ʻia me nā neutrons i loko o kahi reactor nuklea i loaʻa mua ai ke gula artificial. Ua hōʻike ʻia ka ʻāpana metala ma 1955 ma Geneva Atomic Conference.

Fig. 6. Nā ʻātoma ma ka ʻili o ke gula, ʻike ʻia ma ke kiʻi ma kahi microscope tunneling scanning.

7. Hoʻolālā o ka hoʻololi mua ʻana o ke kanaka i nā mea

ʻO ka nūhou o ka hoʻokō ʻana o nā physicists ua hoʻoulu ʻia i kahi pōkole pōkole ma ka honua kūʻai kumukūʻai, akā ua hoʻopiʻi ʻia nā hōʻike nūhou e ka ʻike e pili ana i ke kumukūʻai o ka ʻai i ʻeli ʻia ma kēia ʻano - ʻoi aku ka nui o ka pipiʻi ma mua o ke gula maoli. ʻAʻole e pani nā Reactors i ka mine metala makamae. Akā ʻoi aku ka waiwai o nā isotopes a me nā mea hana i loko o lākou (no ka lāʻau lapaʻau, ka ikehu, ka noiʻi ʻepekema) ʻoi aku ka waiwai ma mua o ke gula.

8. ʻO ka cyclotron mōʻaukala e hoʻohui i nā mea mua ma hope o ka uranium i ka papaʻaina (Lawrence Radiation Laboratory, University of California, Berkeley, ʻAukake 1939)

No ka poʻe heluhelu e makemake ana e ʻimi i nā pilikia i hāpai ʻia ma ka kikokikona, ke paipai nei au i nā ʻatikala a Mr. Tomasz Sowiński. Ua ʻike ʻia ma "Young Technics" ma 2006-2010 (ma lalo o ke poʻomanaʻo "Pehea lākou i ʻike ai"). Loaʻa nā kikokikona ma ka pūnaewele o ka mea kākau ma: .

pōʻai "Me kahi atom no nā makahiki» Ua hoʻomaka ʻo ia me ka hoʻomanaʻo ʻana ua kapa pinepine ʻia ke kenekulia i hala ʻo ka makahiki o ka atom. ʻOiaʻiʻo, ʻaʻole hiki i kekahi ke hoʻomaopopo i nā hoʻokō koʻikoʻi o nā physicists a me nā chemists o ke kenekulia XNUMX i ka hoʻolālā o ka mea. Eia nō naʻe, i nā makahiki i hala iho nei, ʻoi aku ka wikiwiki o ka ʻike e pili ana i ka microcosm, ke hoʻomohala ʻia nei nā ʻenehana e hiki ai ke hoʻololi i nā atom a me nā mole. Hāʻawi kēia iā mākou i ke kuleana e ʻōlelo ʻaʻole i hiki mai ka makahiki maoli o ka atom.