Thaum saib cov khoom siv lead ua thiab lub pov haum, ib tus xav nkag siab tias qhov kev zoo nkauj tsis meej no tuaj yeem tshwm sim li cas, tsim cov haujlwm zoo li no ntawm cov xwm txheej li cas. Muaj lub siab xav kawm ntxiv txog lawv cov khoom. Tom qab tag nrho, qhov tshwj xeeb, tam sim no nyob rau hauv cov xwm txheej rov ua qauv ntawm cov muaju tso cai rau lawv siv txhua qhov chaw: los ntawm cov hniav nyiaj hniav kub mus rau qhov tseeb kev tshawb fawb thiab kev tsim kho tshiab.
Kev tshawb fawb ntawm cov khoom siv crystalline
Cov qauv thiab cov khoom ntawm cov khoom siv lead ua muaj ntau qhov sib txawv uas ib qho kev tshawb fawb cais, mineralogy, koom nrog kev kawm thiab kawm txog cov xwm txheej no. Tus naas ej Lavxias teb sab kws qhia ntawv Alexander Evgenievich Fersman yog li absorbed thiab xav tsis thoob los ntawm ntau haiv neeg thiab infinity ntawm lub ntiaj teb no ntawm crystals uas nws sim captivate ntau lub siab raws li tau zoo raws li lub ntsiab lus no. Nyob rau hauv nws phau ntawv Entertaining Mineralogy, nws zoo siab thiab sov so kom paub txog cov lus zais ntawm cov zaub mov thiab plunge mus rau hauv lub ntiaj teb ntawm lub pov haum:
Kuv xav tau kojcaptivate. Kuv xav kom nej pib xav txog tej roob thiab tej chaw txua txiag zeb, tej mines thiab tej mines, kom nej pib sau tej pob zeb hauv av, kom nej xav mus nrog peb los ntawm lub nroog mus deb deb, mus txog rau ntawm tus dej, qhov chaw ntawd. yog cov pob zeb siab siab, mus rau saum toj los yog mus rau ntug hiav txwv pob zeb, qhov chaw pob zeb tawg, xuab zeb yog mined, lossis ore tawg. Nyob ntawd, txhua qhov chaw koj thiab kuv yuav pom ib yam dab tsi ua: thiab hauv cov pob zeb tuag, xuab zeb thiab pob zeb, peb yuav kawm nyeem qee cov kev cai zoo ntawm cov xwm txheej uas tswj hwm tag nrho lub ntiaj teb thiab raws li lub ntiaj teb tau tsim.
Physics kawm siv lead ua, sib cav hais tias ib lub cev muaj zog tiag tiag yog siv lead ua. Chemistry tshawb xyuas cov qauv molecular ntawm cov muaju, los txog rau qhov xaus tias cov hlau twg muaj cov qauv crystalline.
Kev kawm txog cov khoom muaj txiaj ntsig zoo ntawm cov muaju yog qhov tseem ceeb rau kev txhim kho kev tshawb fawb niaj hnub, thev naus laus zis, kev tsim kho kev lag luam thiab ntau lwm yam lag luam.
Basic laws of crystals
Thawj yam uas tib neeg pom thaum saib cov siv lead ua yog nws cov duab zoo tagnrho, tab sis nws tsis yog qhov tseem ceeb ntawm cov ntxhia lossis hlau.
Thaum lub siv lead ua tawg mus rau hauv me me, tsis muaj dab tsi yuav nyob twj ywm ntawm daim ntawv zoo tagnrho, tab sis ib qho tawg, ib yam li yav dhau los, yuav nyob twj ywm. Ib qho tshwj xeeb ntawm cov siv lead ua tsis yog nws cov tsos, tab sis cov yam ntxwv ntawm nws cov qauv sab hauv.
Symmetrical
Thawj yam uas yuav tsum nco ntsoov thiab nco ntsoov thaum kawm crystals yog qhov tshwm simsymmetry. Nws yog dav nyob rau hauv lub neej niaj hnub. Npauj npaim tis yog symmetrical, ib tug imprint ntawm ib tug blot ntawm ib daim ntawv folded nyob rau hauv ib nrab. Symmetrical snow crystals. Lub hexagonal snowflake muaj rau lub dav hlau ntawm symmetry. Los ntawm khoov daim duab raws ib kab uas piav txog lub dav hlau ntawm symmetry ntawm snowflake, koj muaj peev xwm muab nws ob halves nrog ib leeg.
Lub axis ntawm symmetry muaj xws li cov cuab yeej uas, los ntawm kev tig ib daim duab los ntawm ib co paub lub kaum sab xis nyob ib ncig ntawm nws, nws yog ib qhov ua tau los muab cov khoom tsim nyog ntawm daim duab rau ib leeg. Nyob ntawm qhov loj ntawm lub kaum sab xis uas tsim nyog los ntawm qhov yuav tsum tau tig, axes ntawm 2nd, 3rd, 4th thiab 6th kev txiav txim tau txiav txim siab hauv cov muaju. Yog li, nyob rau hauv snowflakes, muaj ib tug axis ntawm symmetry ntawm lub thib rau kev txiav txim, uas yog perpendicular mus rau lub kos duab dav hlau.
Qhov nruab nrab ntawm symmetry yog qhov taw tes hauv lub dav hlau ntawm daim duab, nyob rau tib qhov kev ncua deb uas nyob rau hauv qhov kev coj rov qab yog tib yam qauv ntawm daim duab.
Dab tsi nyob hauv?
Cov qauv sab hauv ntawm cov muaju yog ib hom kev sib xyaw ntawm cov molecules thiab atoms nyob rau hauv ib qho kev txiav txim peculiar nkaus xwb rau cov muaju. Yuav ua li cas lawv paub cov qauv sab hauv ntawm cov khoom yog tias lawv tsis pom txawm tias muaj lub tshuab tsom iav?
X-ray yog siv rau qhov no. Siv lawv los ua cov pob zeb zoo nkauj, German physicist M. Laue, English physicists leej txiv thiab tus tub Bragg, thiab tus Xib Hwb Lavxias teb sab Yu. Hma tau tsim cov cai raws li cov qauv thiab cov qauv ntawm cov muaju tau kawm.
Txhua yam yog xav tsis thoob thiab xav tsis thoob. Samolub tswv yim ntawm cov qauv ntawm cov molecule tau tig los ua tsis tau rau lub xeev crystalline ntawm teeb meem.
Piv txwv li, xws li cov khoom muaj npe zoo li cov ntsev ntsev muaj cov tshuaj lom neeg ntawm NaCl molecule. Tab sis nyob rau hauv ib tug siv lead ua, ib tug neeg atoms ntawm chlorine thiab sodium tsis ntxiv mus rau cais molecules, tab sis tsim ib tug tej configuration hu ua ib tug spatial los yog siv lead ua lattice. Cov khoom me tshaj plaws ntawm chlorine thiab sodium yog hluav taws xob sib txuas. Crystal lattice ntawm ntsev yog tsim raws li hauv qab no. Ib qho ntawm cov valence electrons ntawm lub plhaub sab nrauv ntawm sodium atom yog nkag mus rau hauv lub plhaub sab nraud ntawm cov tshuaj chlorine atom, uas tsis tau sau tag nrho vim tsis muaj yim electron nyob rau hauv lub plhaub thib peb ntawm chlorine. Yog li, nyob rau hauv ib lub siv lead ua, txhua ion ntawm ob qho tib si sodium thiab chlorine tsis yog ib tug molecule, tab sis mus rau tag nrho cov siv lead ua. Vim qhov tseeb tias cov tshuaj chlorine atom yog monovalent, nws tuaj yeem txuas tsuas yog ib qho hluav taws xob rau nws tus kheej. Tab sis cov yam ntxwv ntawm cov muaju ua rau lub fact tias cov tshuaj chlorine atom nyob ib puag ncig los ntawm rau sodium atoms, thiab nws yog tsis yooj yim sua los txiav txim seb leej twg ntawm lawv yuav muab ib tug electron nrog chlorine.
Nws hloov tawm tias cov tshuaj molecule ntawm cov ntsev ntsev thiab nws cov siv lead ua tsis zoo ib yam. Tag nrho ib qho siv lead ua zoo li ib lub molecule loj.
Grille - qauv nkaus xwb
Qhov yuam kev yuav tsum zam thaum lub spatial lattice raug coj los ua tus qauv tiag tiag ntawm cov qauv siv lead ua. Lattice - ib hom kev cai duab ntawm ib qho piv txwv ntawm kev sib txuas ntawm elementary hais nyob rau hauv cov qauv ntawm cov muaju. Daim phiaj sib txuas cov ntsiab lus nyob rau hauv daim ntawv ntawm cov pobvisually tso cai rau koj los piav txog cov atoms, thiab cov kab txuas lawv yog cov duab kwv yees ntawm kev sib khi rog ntawm lawv.
Hauv kev muaj tiag, qhov sib txawv ntawm cov atoms hauv cov khoom siv lead ua me dua. Nws yog ib tug ntom ntim ntawm nws constituent hais. Lub pob yog ib qho kev xaiv ntawm ib qho atom, kev siv uas ua rau nws muaj peev xwm ua tau kom muaj kev cuam tshuam cov khoom ntawm cov khoom kaw. Nyob rau hauv kev muaj tiag, tsis yog ib tug yooj yim kev sib cuag ntawm atoms, tab sis lawv cov kev sib nrig sib ib feem overlapping ib leeg. Hauv lwm lo lus, daim duab ntawm lub pob nyob rau hauv cov qauv ntawm cov siv lead ua lattice yog, kom pom tseeb, cov duab ntawm ib lub vojvoog uas muaj lub ntsiab ntawm cov electrons ntawm lub atom.
cog lus muaj zog
Muaj lub zog hluav taws xob ntawm kev nyiam ntawm ob qhov sib txawv ntawm cov ions. Nws yog ib qho binder hauv cov qauv ntawm ionic crystals xws li cov lus ntsev. Tab sis yog tias koj coj cov ions ze heev, ces lawv cov electron orbits yuav sib tshooj, thiab cov rog ntawm cov khoom zoo li them nyiaj yuav tshwm sim. Nyob rau hauv cov khoom siv lead ua, kev faib tawm ntawm ions yog xws li tias lub zog txaus ntshai thiab ntxim nyiam nyob hauv qhov sib npaug, muab lub zog crystalline. Cov qauv no yog ib txwm siv rau ionic crystals.
Thiab nyob rau hauv cov siv lead ua lattices ntawm pob zeb diamond thiab graphite muaj kev sib txuas ntawm atoms nrog kev pab los ntawm cov khoom siv (sib sau ua ke) electrons. Nyob ze cov atoms muaj cov electrons uas tig ib ncig ntawm lub nucleus ntawm ob qho tib si thiab cov atoms nyob sib ze.
Kev kawm ntxaws txog txoj kev xav ntawm lub zog nrog cov ntawv cog lus no nyuaj heev thiab nyob hauv thaj chaw ntawm quantum mechanics.
Metal Differences
Cov qauv ntawm cov hlau siv lead ua yog qhov nyuaj dua. Vim qhov tseeb tias cov hlau atoms yooj yim pub dawb rau cov khoom siv hluav taws xob sab nraud, lawv tuaj yeem txav mus los thoob plaws tag nrho cov ntim ntawm cov siv lead ua, tsim cov roj hluav taws xob hauv nws. Ua tsaug rau xws li "wandering" electrons, rog yog tsim los xyuas kom meej lub zog ntawm cov hlau ingot. Txoj kev tshawb fawb ntawm cov qauv ntawm cov hlau tiag tiag qhia tau hais tias, nyob ntawm txoj kev ua kom txias ntawm cov hlau ingot, nws yuav muaj qhov tsis zoo: nto, taw tes thiab tawm. Qhov luaj li cas ntawm qhov tsis xws luag tsis tshaj txoj kab uas hla ntawm ob peb atoms, tab sis lawv distort lub siv lead ua lattice thiab cuam tshuam cov txheej txheem diffusion hauv hlau.
Crystal Growth
Rau kev nkag siab yooj yim dua, kev loj hlob ntawm cov khoom siv lead ua tuaj yeem sawv cev raws li kev txhim kho ntawm cov qauv cib. Yog hais tias ib qho cib ntawm ib qho tsis tiav masonry tau nthuav tawm raws li ib feem tseem ceeb ntawm cov siv lead ua, ces nws muaj peev xwm txiav txim siab qhov twg siv lead ua yuav loj hlob. Lub zog ntawm cov khoom siv lead ua yog xws li cov cib tso rau ntawm thawj cib yuav muaj kev nyiam los ntawm ib sab - los ntawm hauv qab. Thaum tso rau ntawm qhov thib ob - los ntawm ob sab, thiab ntawm peb - los ntawm peb. Nyob rau hauv tus txheej txheem ntawm crystallization - kev hloov ntawm cov kua mus rau ib tug khoom lub xeev - lub zog (kub ntawm fusion) yog tso tawm. Rau lub zog loj tshaj plaws ntawm lub cev, nws lub zog ua tau yuav tsum zoo li tsawg kawg nkaus. Yog li ntawd, kev loj hlob ntawm crystals tshwm sim txheej los ntawm txheej. Ua ntej, ib kab ntawm lub dav hlau yuav ua tiav, tom qab ntawd tag nrho lub dav hlau, thiab tom qab ntawd tus tom ntej yuav pib ua.
Science ofcrystals
Txoj cai lij choj ntawm crystallography - kev tshawb fawb ntawm cov muaju - hais tias txhua lub kaum sab xis ntawm cov dav hlau sib txawv ntawm cov ntsej muag siv lead ua ib txwm nyob tas li thiab tib yam. Txawm li cas los xij distorted ib tug loj hlob siv lead ua yog, lub kaum sab xis ntawm nws lub ntsej muag khaws tib tus nqi uas muaj nyob rau hauv hom no. Txawm hais tias qhov loj me, zoo li cas, thiab tus naj npawb, lub ntsej muag ntawm tib lub dav hlau siv lead ua ib txwm sib tshuam ntawm tib lub kaum sab xis. Txoj cai tswjfwm ntawm cov kaum sab xis tau tshawb pom los ntawm M. V. Lomonosov xyoo 1669 thiab ua lub luag haujlwm tseem ceeb hauv kev kawm txog cov qauv ntawm cov muaju.
Anisotropy
Qhov peculiarity ntawm cov txheej txheem ntawm kev tsim siv lead ua yog vim muaj qhov tshwm sim ntawm anisotropy - cov yam ntxwv ntawm lub cev sib txawv nyob ntawm txoj kev loj hlob. Ib leeg siv lead ua hluav taws xob, cua sov thiab lub teeb sib txawv ntawm cov lus qhia sib txawv thiab muaj lub zog tsis sib xws.
Yog li, tib cov tshuaj lom neeg nrog tib lub atoms tuaj yeem tsim cov khoom siv lead ua sib txawv. Piv txwv li, carbon tuaj yeem crystallize rau hauv pob zeb diamond thiab rau hauv graphite. Nyob rau tib lub sijhawm, pob zeb diamond yog ib qho piv txwv ntawm lub zog siab tshaj plaws ntawm cov zaub mov, thiab graphite yooj yim tawm ntawm nws cov nplai thaum sau ntawv nrog xaum rau ntawm daim ntawv.
Kev ntsuas lub kaum sab xis ntawm lub ntsej muag ntawm cov zaub mov yog qhov tseem ceeb tshaj plaws rau kev txiav txim siab lawv qhov xwm txheej.
Basic nta
Tom tau kawm cov yam ntxwv ntawm cov khoom siv lead ua, peb tuaj yeem piav qhia luv luv ntawm lawv cov khoom tseem ceeb:
- Anisotropy - cov khoom tsis sib xws hauv cov lus qhia sib txawv.
- Uniformity - elementaryCov khoom siv ntawm cov muaju, sib npaug sib npaug, muaj cov khoom qub.
- Lub peev xwm los txiav nws tus kheej - ib qho ntawm cov khoom siv lead ua hauv nruab nrab uas haum rau nws txoj kev loj hlob yuav siv ntau yam duab thiab yuav npog nrog lub ntsej muag sib xws rau hom crystals no. Nws yog cov cuab yeej no uas tso cai rau cov siv lead ua kom nws cov symmetry.
- Qhov sib txawv ntawm qhov melting point. Kev puas tsuaj ntawm cov kab lattice ntawm cov ntxhia, uas yog, kev hloov pauv ntawm cov khoom siv crystalline los ntawm cov khoom mus rau lub xeev ua kua, ib txwm tshwm sim ntawm qhov kub thiab txias.
Crystals yog cov khoom uas tau coj lub ntuj zoo ntawm ib qho symmetrical polyhedron. Cov qauv ntawm cov muaju, tus yam ntxwv los ntawm kev tsim ntawm ib qho chaw spatial lattice, tau ua lub hauv paus rau kev txhim kho hauv physics ntawm txoj kev xav ntawm cov qauv hluav taws xob ntawm cov khoom. Kev kawm txog cov khoom thiab cov qauv ntawm cov zaub mov yog qhov tseem ceeb ntawm kev siv.
