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Sc, Y, La subgroup Ce family (lanthanides) Th family (actinides) General properties Electronic configuration Compare the electronic config.of these elements (and their ! ions) ith that of #l and of Ga subgroup (Ga,$n,Tl) Conclusion % the elements of Ga subgroup have a similar atomic structure to Al in the ground state but sharply different structures of their E 3+ ions. Element, $on& le'el ( L ) * #l + , ! Ga + , -, ! Sc + , . + #l ! + , , Ga ! + , -, Sc ! + , , #s a conse/uence% the propert
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  Sc, Y, La subgroupCe family (lanthanides)Th family (actinides)General propertiesElectronic configurationCompare the electronic config.of these elements (and their ! ions) ith that of #l and of Ga subgroup (Ga,$n,Tl)Conclusion % the elements of Ga subgroup have a similar atomic structure to Al in theground state but sharply different structures of their E  3+ ions. Element, $on& le'elL* #l+!Ga+-!Sc++ #l ! +Ga ! +-Sc ! + #s a conse/uence% the properties of similar compounds in the series B,Al,Sc….Ac change uniformly, in contrast to the B,Al,Ga….l series compare for e0ample % 1 atomic and ionic radii 1the heats of formation of the highest o0ides in the series 213La (  p and d elements ) ith that in 2 43. Tl series (  p elements  only). 5hat is obser'ed6 E0plainElement2#lScYLa#c78-!+-!89 #-:.-+;.<<.8.-!.=++9>?alencyelectron+s + +p - !s + !p - !d - <s + <d - 8s + 8d - ;s + ;d - 9s +  #tomic radius:.--.<!-.;<-.--.9+.:!$onic radius,E ! :.+-:.89:.!:.9-.:<-.--1 ∆ @ + (AB&mol)E +  ! -<;--;9:-9-8-<--:+2 +  !  #l +  ! Ga +  ! $n +  ! Tl +  ! 1 ∆ @ + (AB&mol)-<;--;9:-:9--::<8:+etallic properties$ncreases regularly in the seriesClarA-: 1! -: 1! -: 1! -: 1 Electrochemical character Sc and its analogues are far in front of hydrogenSc is slightly more metallic than #l, but resembles it in % 1 reacts 'igorously ith @ +  hen the protecti'e o0ide layer is remo'ed 1 hydrous o0ide, Sc +  ! .0 @ +  is amphoter  1 only compounds in ! o0idation state are formed 1 in its compounds, C.* greater ; are unAno n  1 there is no e'idence for a lo er .S although are Ano n phases ith unusualstoichiometrie liAe% 1 Sc$ +.-9 ,Sc2r  +.!1 Sc analogues are closer in their properties ith alAaline earth metals (Ca)ccurrence 1 are 'ery dispersed, do not form separate mineralsDreparation % -.1 electrolysis of molten chlorides 1  +.1 metallothermic reduction % 1  ScCl !   Ca (-::: : C) →  Sc  CaCl +1  Ln +  !   La (more -::: : C) →  Ln  La +  ! eacti'ity 1 increases do n the group (liAe s  group elements) 1 ith nonmetals 4at ele'ated temperatures 1 ith diluted acids% Sc, Y, LaM 2 O 3 , M 2 S 3 MX 3 MNLa(OH) 3 X 2  N 2 ionic carbidesCO 2 , SH 2 O (t 0 C)H 2 , B,C, SiMxEyinterstitiaco! o#ndsacidsMX 3   $  H 2 (HC ,HNO 3 , H 2 SO % ) $ &et air M(OH) 3  the interstitial compounds are high melting compounds of metallic type ith lo 1acti'e nonmetals5hat are high1temperature superconductors6 #t ordinary temperatures, metals ha'e some resistance to the flo of electrons, dueto 'ibration of the atoms hich scatter the electrons. #s the temperature is lo ered, the atoms 'ibrate less and the resistance decreases,until the materialFs critical temperature,T C  is reached. #t this temperature , theresistance drops abruptly to ero.H --- 4 nnes,a Iutch physicist disco'ered that @g loses all resistance to electricalflo hen cooled to about <, a current once started ill flo continuously(superconducti'ity)-!! 1Superconductors are also perfectly diamagnetic (repel a magnetic field)eissner effect # magnetic field induces a current in a conductorHcon'ersely, a current induces amagnetic field5hen a magnet approches a superconductor, it induces a current in thesuperconductor.2ecause there is no resistance to the current, it continues to flo ,thus inducing its o n magnetic field hich then repels the magnetFs field.$f themagnet is sufficiently small and strong, the repulsion ill be enough tocounterbalance the pull of gra'ity and the magnet ill le'itate abo'e the surface of the superconductor.E'olution of superconducti'ity%  -912ednor, uller 4 $2 7urich (noble prie)+ 1first ceramic superconductor Y2C (-%+%!1Y2a + Cu !  91 δ )is an o0ygen1deficient triple pero'sAite (#2 ! ) !  # J central cations Y and 2a H 2J Cu cationstoday 4 -+8  superconductor     YBCO  YBCO is an oxygen-deficient triple perovskite, A 3 B 3 O 9-x  where Y and Ba are thecentral A cations and Cu the B cation Oxygen is !issing fro! the central Ylayer and fro! the a-  axis of the asal plane . #erovskite structure, AB$ 3 The A  atoms occupy the central positions and are coordinated to -+ K ions B  atoms are at the cell corners and are octahedrally coordinated.Typically 2 atoms are transition metals and # atoms are large, electropositi'e atoms such as 2a, La Cu%&' is coordinated to ( oxygens in a s)uare planar configuration,corner-sharing to for! chains along the -axisCu%&&' is s)uare-pyra!idally coordinated, with the CuO *  unitscorner-sharing to for! uckled sheets in a-b  plane+he oxygen stoichio!etry of YBCO can vary over the range       .whilst retaining the triple perovskite structure/ properties rangefro! superconducting %*      .' to se!iconducting %   ('
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