Lanthanides thiab actinides: txoj hauj lwm nyob rau hauv lub periodic system

Txhua yam ntawm cov tshuaj hais qhia nyob rau hauv lub ntiaj teb zoo li: cov cua thiab hydrosphere lithosphere - yuav pab raws li ib tug kaj piv txwv lees tias yuav tsum muaj atomic thiab molecular tej lus qhia periodic txoj cai. Lawv formulated los ntawm lub luminaries of Natural History - Lavxias teb sab zaum M. V. Lomonosovym thiab D. I. Mendeleevym. Lanthanides thiab Actinides - ob tsev neeg, uas comprise 14 tshuaj hais, raws li tau zoo raws li co lawv tus kheej - lanthanum thiab actinium. Lawv lub zog - ob lub cev thiab tshuaj - yuav tsum tau nyob los ntawm peb nyob rau hauv no ua hauj lwm. Nyob rau hauv tas li ntawd, peb txiav txim rau txoj hauj lwm nyob rau hauv lub periodic system ntawm hydrogen, lanthanides, actinides nyob rau cov qauv ntawm cov electron orbitals ntawm atoms.

Keeb kwm ntawm foundations

Nyob rau hauv lub lig 18th xyoo pua Yu gadolinium twb tau los ntawm thawj compound los ntawm cov pab pawg neeg ntawm tsawg lub ntiaj teb hlau - oxide ntawm yttrium. Kom txog thaum lub thaum ntxov 20th xyoo pua, ua tsaug rau kev tshawb fawb los ntawm G. Moseley nyob rau hauv Science News for KIDS ua paub txog lub hav zoov ntawm ib pab pawg neeg ntawm cov hlau. Lawv nyob rau hauv lub periodic rooj ntawm lanthanum thiab hafnium. Lwm tshuaj caij - actinium, lanthanum zoo li, cov ntaub ntawv ib tsev neeg ntawm 14 tej tshuaj hais, cov actinides. Lawv foundations nyob rau hauv science tshwm sim txij li thaum xyoo 1879, kom txog thaum lub nruab nrab-xyoo pua 20th. Lanthanides thiab actinides muaj ib tug ntau zoo sib xws nyob rau hauv lub cev thiab tshuaj zog. Qhov no yuav tau piav arrangement ntawm electrons nyob rau hauv lub atoms ntawm cov hlau, uas yog nyob rau hauv lub zog ntau ntau, namely lanthanide yog thib plaub theem ntawm f-sublayer, thiab rau actinides - thib tsib theem ntawm f-sublayer. Tom ntej no, peb xav txog lub electron zoo li ntawm atoms ntawm cov saum toj no-hais co nyob rau hauv ntau yam.

Tus qauv ntawm lub puab kev hloov ntsiab nyob rau hauv lub teeb ntawm lub atomic-molecular kev tshawb xav

Ci ntsa iab foundations ntawm cov qauv ntawm cov tshuaj M. V. Lomonosova yog lub hauv paus rau koj kawm ntxiv txog lub electron zoo li ntawm atoms. Rutherford qauv ntawm elementary particle qauv ntawm ib tug tshuaj caij, lub Max Planck kev tshawb fawb, F. Hund pub chemists mus nrhiav qhov tseeb piav qhia txog cov uas twb muaj lawm kev cai ntawm lub periodic variation ntawm lub cev thiab tshuaj zog, uas yog tsiag ntawv los ntawm lanthanides thiab actinides. Koj yuav tsis quav ntsej qhov tseem ceeb heev luag hauj lwm ntawm lub periodic txoj cai D. I. Mendeleeva nyob rau hauv txoj kev tshawb no ntawm cov qauv ntawm cov atoms ntawm txoj kev hloov ntsiab. Cia peb kawm no qhov teeb meem nyob rau hauv ntau yam.

Muab puab kev hloov ntsiab nyob rau hauv lub periodic system D. I. Mendeleeva

Nyob rau hauv lub thib peb pab pawg ntawm lub thib rau - ib tug ntev lub sij hawm - rau tsev neeg hlau yog lanthanum, cerium thiab cov txheej txheem rau lutetium inclusive. Thaum lanthanum atom 4F-sublayer npliag thiab tag lawm ua tus sau nyob rau hauv lutetium 14th electrons. Thaum ntsiab pov tseg therebetween, muaj yog ib tug gradual filling ntawm f-orbitals. Nyob rau hauv lub tsev neeg ntawm actinides - los ntawm thorium rau lawrencium - Txoj ntsiab cai tib yog cai txuam nrog ntawm negatively them hais nrog tus tsuas yog sib txawv uas tshwm sim nyob rau hauv lub teb electrons 5F-sublayer. Tus qauv ntawm cov sab nraud muaj zog thiab tus naj npawb ntawm tsis zoo hais nyob saud (sib npaug zos rau ob tug) nyob rau hauv tag nrho cov saum toj no co tib. Qhov tseeb teb rau lo lus nug hais txog vim li cas lub lanthanides thiab actinides, hu ua lub puab kev hloov hais, muaj ntau yam zoo sib xws.

Ib co kev pab ntawm cov tshuaj cov ntaub ntawv ntawm ob tsev neeg ua ke rau hauv lub thib ob sab ntawm lub pab pawg. Lawv muaj ob hlau los ntawm txhua tus hauv tsev. Nyob rau hauv lub luv luv hauv daim ntawv ntawm cov periodic system ntawm tshuaj ntsiab DI Mendeleev cov neeg sawv cev ntawm cov tsev neeg yog cais los ntawm lub rooj nws tus kheej thiab cov txheej txheem ntawm cais kab. Yog li ntawd, txoj hauj lwm ntawm actinides thiab lanthanides nyob rau hauv lub periodic system hnov cov kev npaj ntawm cov qauv ntawm cov atoms thiab electrons nyob rau hauv puab periodicity sau ntau ntau thiab muaj cov tib yam oxidation tshwm sim los aggregating nrog txoj kev hloov co nyob rau hauv lub general pab pawg neeg. Nyob rau hauv cov tshuaj hais muaj nta thiab cov khoom sib npaug lanthanum los yog actinium. Yog vim li cas lub lanthanides thiab actinides muab tshem tawm los ntawm lub rooj ntawm tshuaj ntsiab.

Raws li cov hluav taws xob configuration ntawm f-sublayer influences lub thaj chaw ntawm cov hlau

Raws li peb tau hais ua ntej, rau txoj hauj lwm ntawm lanthanides thiab actinides nyob rau hauv lub periodic system ncaj qha thiab txiav txim seb lawv lub cev thiab tshuaj cov yam ntxwv. Piv txwv li, cerium ions, gadolinium, thiab lwm yam hais txog lub lanthanide tsev neeg muaj siab magnetic moments vim lub yam ntxwv nta ntawm f-sublayer. Nws yog tej zaum yuav siv hlau li dopants rau cov semiconductors nrog sib nqus. Sulfides tsev neeg hais actinium (e.g., sulfide protactinium, thorium) nyob rau hauv lawv cov molecules muaj ib tug tov hom tshuaj tsevneeg: ionic-covalent los yog covalent-nws yog xim hlau. Qhov no yam ntxwv feature tau coj mus rau lub rov tshwm sim ntawm tshiab lub cev thiab tshuaj zog thiab ua hauj lwm raws li ib lo lus teb rau lo lus nug ntawm yog vim li cas lub lanthanides thiab actinides muaj fluorescent zog. Piv txwv li, ib tug qauv ntawm actinium nyiaj glows nyob rau hauv qhov tsaus ntuj nti xiavlus ci ntsa iab. Qhov no yog vim qhov kev txiav txim ntawm lub fais tam sim no hlau ions, photons ntawm lub teeb, uas tshwm sim nyob rau hauv tus ntawm lub excitation ntawm cov atoms thiab electrons nyob rau ntawd "dhia" rau ib tug ntau dua lub zog theem thiab ces rov qab mus rau lawv nyob ruaj ruaj orbit. Nws yog vim li no hais tias tus lanthanides thiab actinides yog phosphors.

Lub txim ntawm kev txo lub ionic radii ntawm lub atoms

Thaum lanthanum thiab actinium, zoo li hais los ntawm lawv cov tsev neeg, ib tug monotonic txo nyob rau hauv loj indicators radii ntawm hlau ions. Nyob rau hauv Science News for KIDS, nyob rau hauv xws li mob hais lus ntawm qhov lanthanide thiab actinide compression. Cov Science News for KIDS teem nram qab no qauv: nrog ua them nyiaj ntawm lub nucleus ntawm atoms, thaum lub ntsiab yuav mus rau ib tug thiab tib lub sij hawm thiab lawv radii txo. Qhov no yuav tau piav raws li nram no: rau co xws li cerium, praseodymium, neodymium, tus xov tooj ntawm lub zog theem ntawm atoms thiab yeej ib txwm sib npaug zos rau. Txawm li cas los nuclei nqi feem incremented los ntawm ib tug thiab roos +58, +59, +60. Qhov no txhais tau tias tsub kom tus quab yuam ntawm attraction ntawm lub puab zoo li ntawm electrons mus rau lub zoo them nucleus. Raws li ib tug tsim nyog tau muaj ib tug yuav txo tau ntawm lub radii ntawm lub atoms. Lub ionic hlau tebchaw nrog ua atomic tooj ntawm cov ionic radii kuj txo. Zoo ib yam li cov kev hloov muaj cai nyob rau hauv lub ntsiab actinium tsev neeg. Yog vim li cas lub lanthanides thiab actinides yog hu ua menyuam ntxaib. Txo ion radii ua feem ntau mus rau ib tug weakening ntawm qhov yooj yim zog ntawm hydroxides ntawm Ce (OH) _3, Pr (OH) _3, thiab yog lub hauv paus ntawm lutetium twb exhibits amphoteric zog.

Npaj txhij tau ua sau 4F-sublevel unpaired electrons nyob rau hauv orbitals rau ib nrab ntawm cov europium atom. Nws Atom voos kheej-kheej yog tsis txo, tab sis, theej nce. Nyob rau hauv cov nram qab no nws nyob rau hauv lub series ntawm lanthanides gadolinium 5D-sublevel, muaj ib tug electron 4F-sublevel zoo xws li cov EU. Xws li ib tug qauv ua ib tug ceev txo nyob rau hauv lub voos kheej-kheej ntawm gadolinium atoms. Ib tug zoo xws li cov phenomenon yog cai nyob rau hauv ib tug khub ntawm ytterbium - lutetium. Tus thawj lub caij ntawm lub atom voos kheej-kheej ntawm ib tug loj vim mus ua kom tiav sau 4F-sublayer, thaum lutetium nws dheev txo raws li nyob rau 5D-sublevel electron cai tsos. Nyob rau hauv actinium thiab lwm yam tej ntsiab nyob rau hauv tsev neeg no radii ntawm atoms thiab ions tsis hloov monotonically, tab sis raws li zoo raws li hais tias ntawm lub lanthanides, nyob rau hauv leaps thiab ciam teb. Yog li, lub lanthanides thiab actinides yog hais nyob rau hauv uas lub thaj chaw ntawm lawv lub tebchaw correlatively nyob rau hauv lub ionic voos kheej-kheej thiab cov qauv ntawm cov electron zoo li ntawm cov atoms.

valence lub xeev

Lanthanides thiab Actinides yog hais uas nws cov yam ntxwv yog heev uas zoo sib xws. Nyob rau hauv kev, nws txhawj xeeb lawv oxidation lub xeev nyob rau hauv lub valence ions thiab atoms. Piv txwv li, thorium, protactinium, seeb ib valency ntawm peb, nyob rau hauv lub tebchaw ntawm Th (OH) _3, PaCl _3, ThF _3, Pa ₂ (CO _{3) 3.} Tag nrho cov ntawm cov tshuaj yog insoluble thiab muaj ib yam tshuaj uas muaj zog raws li cov hlau los ntawm lanthanum tsev neeg: .., cerium, praseodymium, neodymium, thiab thiaj li tawm nyob rau hauv Lanthanides ntawm cov tebchaw yuav kuj yuav trivalent. Cov piv txwv ua pov thawj rau hauv lub correctness ntawm peb assertion tias cov lanthanides thiab actinides - menyuam ntxaib. Lawv muaj xws li cov lub cev thiab tshuaj zog. Qhov no yuav tau piav feem ntau cov qauv ntawm cov electron orbitals nyob rau hauv atoms ntawm ob tsev neeg ntawm sab hauv txoj kev hloov mus hais.

hlau zog

Tag nrho cov neeg sawv cev ntawm ob pawg yog co uas tau ua tiav 4f-, 5f-, raws li zoo raws li d-sublevels. Lanthanum thiab cov ntsiab ntawm cov uas tsis tshua muaj lub ntiaj teb hu ua nws tsev neeg. Lawv lub cev thiab tshuaj cov yam ntxwv yog li ntawd, zoo ib yam li hais tias nyias nyob rau hauv laboratory tej yam kev mob, lawv raug sib cais uas nyuaj heev. Uas qhia feem ntau yog cov oxidation xeev +3, lanthanum series ntsiab muaj ntau yam zoo sib xws nrog alkaline ntiaj teb co (barium, calcium, strontium). Actinides yog kuj tsis tshua muaj active co nyob rau hauv tas li ntawd kuj tej.

Lub Khoos Loos Tsev nta ntawm lub lanthanides thiab actinides thiab kov zog xws li, piv txwv li, finely faib pyrophoric. Muaj kuj yog ib tug yuav txo tau nyob rau hauv lub loj ntawm cov hlau ntsej muag-rau nruab nrab crystalline lattices. Ntxiv tias tag nrho cov tshuaj hais ntawm ob tsev neeg - ib tug hlau nrog ib tug silvery sheen, vim lub high reactivity ntawm lub sai tsaus huab cua. Lawv them los ntawm cov oxide zaj duab xis tiv thaiv los ntawm ntxiv oxidation. Tag nrho cov ntsiab yog txaus refractory tsuas yog neptunium, thiab plutonium, lub melting kub yog ho hauv qab no 1000 ° C.

Yam ntxwv tshuaj

Raws li sau tseg ua ntej lawm, tus lanthanides thiab actinides sib active hlau. Yog li, lanthanum, cerium thiab lwm tus neeg hauv tsev neeg tau yooj yim yuav kev cob cog rua nrog tej yam yooj yim tshuaj - halogens, raws li zoo raws li phosphorus, carbon. Lanthanides kuj nrog ob carbon monoxide thiab cov pa roj carbon dioxide. Lawv yog cov tseem muaj cuab kav mus decompose dej. Dhau li tej yam yooj yim ntsev, xws li e.g. SeCl ₃ los yog PrF _3, lawv tsim ob ntsev. Nyob rau hauv analytical Science News for KIDS, nyob ib qho tseem ceeb qhov chaw cov tshuaj tiv thaiv nrog lub lanthanide hlau-glycine thiab citric acids. Cov uas ua txoj tebchaw xws dab yog siv rau lub sib cais ntawm ib tug sib tov ntawm lanthanides, xws li ores.

Los ntawm cov tshuaj tiv thaiv nrog ib tug nitrate, chloride thiab sulfate acids, co rau coj cov ntsev. Lawv yog cov yooj yim soluble nyob rau hauv cov dej thiab yog yooj yim muaj peev xwm ntawm txoj kev crystalline hydrates. Nws yuav tsum tau muab sau tseg tias aqueous lub ntsiab ntawm lanthanide ntsev yog dawb, uas yog piav los ntawm tus muaj nyob rau hauv lawv cov ions. ntsev dlaws samarium los yog praseodymium ntsuab neodymium - liab-liab doog, europium thiab promethium - liab. Txij li thaum lub ions nyob rau hauv oxidation xeev +3 yog dawb, nws yog siv nyob rau hauv analytical Science News for KIDS rau lub Nov ntawm hlau ions, lanthanides (thiaj li hu ua high-zoo tshuaj tiv thaiv). Rau tib lub hom phiaj kuj yog siv txoj kev tshuaj ntsuam xyuas xws li fractional crystallization thiab ion pauv chromatography.

Nyob rau hauv ob ntawm lub actinides pab pawg neeg ntawm cov ntsiab peev xwm yuav txawv. Qhov no yog Berkeley, ua liaj ua teb, mendelevium, nobelium, lawrencium thiab uranium, neptunium, plutonium, omeretsy. Tshuaj zog yog zoo ib yam li ib tug thawj thiab lanthanum co ntawm nws tsev neeg. Hais ntawm lub thib ob pab pawg neeg muaj heev zoo xws li cov tshuaj yam ntxwv (tshuam zoo tib yam rau txhua tus lwm yam). Tag nrho actinides sai sai nrog uas tsis yog-hlau: leej faj, nitrogen, carbon. Nrog rau oxygen legandami lawv tsim txoj tebchaw. Raws li yuav pom, ob tsev neeg ntawm cov hlau zoo xws li cov txhua lwm yam nyob rau hauv cov tshuaj coj tus cwj pwm. Yog vim li cas lub lanthanides thiab actinides co feem ntau hu ua ntxaib.

Qhov teeb meem no hydrogen periodic system, lub lanthanides, lub actinides

Nws yog tsim nyog los noj mus rau hauv tus account lub fact tias hydrogen yog sufficiently reactive substance. Nws manifests nws tus kheej, nyob ntawm seb cov tshuaj cov tshuaj tiv thaiv tej yam kev mob: raws li ib tug txo neeg saib xyuas thiab oxidizing neeg sawv cev. Uas yog vim li cas nyob rau hauv lub periodic system, hydrogen yog ib txhij nyob rau hauv loj pab pawg ntawm cov ob pawg.

Tus thawj hydrogen ua raws li ib tug txo neeg sawv cev, raws li zoo raws li alkali hlau, nyob ntawm no. Hydrogen nyob rau hauv qhov chaw ntawm lub 7 pab pawg neeg nrog rau cov ntsiab halogens qhia nws nyiaj kom dhau. Nyob rau hauv lub thib rau lub sij hawm nws yog, raws li yav tas los hais, lub tsev neeg ntawm lanthanides, nws nyob rau hauv ib tug nyias muaj nyias ib kab rau yooj yim thiab compactness ntawm lub rooj. Xya lub sij hawm muaj ib tug pab pawg neeg ntawm tej ntsiab nrog cov yam ntxwv zoo xws li cov actin. Actinides yog nyob sab nraum lub rooj tshuaj ntsiab DI Mendeleev nyob rau hauv nyob ze lanthanum tsev neeg. Cov ntsiab ntawm lub kawg kawm, txij thaum lub nucleus ntawm lawv atoms yog heev tsis ruaj tsis khov vim lub radioactivity. Nco qab tias lub lanthanides thiab actinides yog internal hloov hais, thiab lawv physicochemical yam ntxwv yog heev uas zoo sib xws.

General txoj kev ua hlau kev lag luam

Tshwj thorium, protactinium thiab uranium, uas yog ua los ntawm ncaj qha los ntawm ores, lwm yam actinides yuav tsum npaj kom txhij los ntawm irradiating kuaj ntawm uranium hlau flows ceev mus neutrons. Nyob rau hauv industrial scale neptunium thiab plutonium yog muab rho tawm los ntawm siv roj los ntawm nuclear reactors. Nco ntsoov tias tau actinides - yog haum complex thiab kim txheej txheem, lub ntsiab txoj kev uas yog ion pauv thiab multistage extraction. Lanthanides, uas yog hu ua tsawg lub ntiaj teb hais, tau los ntawm electrolysis ntawm chlorides los yog fluorides. Yog xav tau ultrapure lanthanides, siv metallothermal txoj kev.

Qhov twg thov nrog txoj kev hloov cov ntsiab

Lub spectrum ntawm kev siv ntawm co uas peb kawm no kuj yog sab. Rau ib tsev neeg ntawm actinium - yog, saum toj no tag nrho, nuclear riam phom thiab lub zog. Actinides yog ib qho tseem ceeb nyob rau hauv cov tshuaj, qhov khuam kom paub tias, ua kom tsom xam. Nws yog tsis yooj yim sua rau tsis quav ntsej txog kev siv ntawm lanthanides thiab actinides, raws li neutron capture nyob rau hauv nuclear reactors qhov chaw. Lanthanides kuj siv tau raws li alloying ntxiv rau hlau thiab hlau, raws li zoo raws li nyob rau hauv qhuav ntawm phosphors.

Faib nyob rau hauv cov xwm

Oxides ntawm actinides thiab lanthanides yog feem ntau hu ua zirconium, thorium, yttrium earths. Lawv yog ib tug loj qhov twg los rau qhov kev npaj ntawm cov coj co. Uranus, raws li lub ntsiab tus neeg sawv cev ntawm lub actinides yog nyob rau hauv tus txheej txheej ntawm cov lithosphere nyob rau hauv daim ntawv ntawm cov plaub hom ores los yog lwm yam minerals tawm. Ua ntej ntawm tag nrho cov, nws yog pitchblende, uas yog uranium dioxide. Nws yog ib lub siab cov ntsiab lus ntawm cov hlau. Feem ntau nrog radium uranium dioxide deposits (leeg). Lawv muaj nyob rau hauv Canada, Fabkis, Zaire. Ceg thorium thiab uranium ores feem ntau muaj lwm yam ores uas zoo co, xws li kub los yog nyiaj.

Cov lus nug ntawm tej raw cov ntaub ntawv nplua nuj nyob rau hauv Russia, South Africa, Canada thiab Australia. Ib txhia sedimentary pob zeb muaj lub mineral carnotite. Nws qauv, nyob rau hauv tas li ntawd mus uranium, vanadium thiab nkag mus rau lwm tus. Qhov thib plaub hom nyoos uranium - ib tug phosphate ore thiab zhelezouranovye slates. Lawv reserves yog nyob rau hauv Morocco, Sweden thiab lub tebchaws United States. Cov tam sim no xam tau tias yog pheej ua deposits ntawm thee thiab lignite muaj uranium impurities. Lawv yog ua nyob rau hauv Spain, lub Czech koom pheej, raws li zoo raws li ob tug US lub xeev - North thiab South Dakota.