Editing Group 3 element (section)

==Composition==
{{Periodic table (micro)|mark=Sc,Y,Lu,Lr|title=Group&nbsp;3: Sc, Y, Lu, Lr [[Image:Yes check.svg|15px|Correct]]}}
{{Periodic table (micro)|form=Sc, Y, La, Ac|mark=Sc,Y,La,Ac|title=Group&nbsp;3: Sc, Y, La, Ac [[Image:X mark.svg|15px|Incorrect]]}}
Physical, chemical, and electronic evidence overwhelmingly shows that the correct elements in group 3 are scandium, yttrium, lutetium, and lawrencium:<ref>Rothbaum, J. O.; Motta, A.*; Kratish, Y.*; Marks, T.J.* Chemodivergent Organolanthanide Catalyzed C-H a-Mono-Borylation of Pyridines. J. Am. Chem. Soc. 2022, 144, 17086-17096: https://pubs.acs.org/doi/10.1021/jacs.2c06844</ref><ref name="Jensen2015">{{cite journal |last1=Jensen |first1=William B. |date=2015 |author-link=William B. Jensen |title=The positions of lanthanum (actinium) and lutetium (lawrencium) in the periodic table: an update |url=https://link.springer.com/article/10.1007/s10698-015-9216-1 |journal=Foundations of Chemistry |volume=17 |issue= |pages=23–31 |doi=10.1007/s10698-015-9216-1 |s2cid=98624395 |access-date=28 January 2021 |archive-date=30 January 2021 |archive-url=https://web.archive.org/web/20210130011116/https://link.springer.com/article/10.1007/s10698-015-9216-1 |url-status=live |url-access=subscription }}</ref><ref name="Fluck">{{cite journal |last1=Fluck |first1=E. |year=1988 |title=New Notations in the Periodic Table |journal=[[Pure and Applied Chemistry|Pure Appl. Chem.]] |volume=60 |pages=431–436|doi=10.1351/pac198860030431 |url=https://www.iupac.org/publications/pac/1988/pdf/6003x0431.pdf |access-date=24 March 2012 |issue=3 |s2cid=96704008 |url-status=live |archive-url=https://web.archive.org/web/20120325152951/https://www.iupac.org/publications/pac/1988/pdf/6003x0431.pdf |archive-date=25 March 2012}}</ref><ref name="Jensen1982">{{cite journal |title=The Positions of Lanthanum (Actinium) and Lutetium (Lawrencium) in the Periodic Table |first=William B. |last=Jensen |author-link=William B. Jensen |journal=J. Chem. Educ. |year=1982 |volume=59 |issue = 8|pages=634–636 |doi=10.1021/ed059p634|bibcode=1982JChEd..59..634J }}</ref><ref name=Landau>{{cite book
 |author=[[Lev Landau|L. D. Landau]], [[Evgeny Lifshitz|E. M. Lifshitz]]
 |year=1958
 |title=Quantum Mechanics: Non-Relativistic Theory
 |edition=1st |volume=3
 |publisher=[[Pergamon Press]]
 |pages=256–7
}}</ref><ref name="Wittig">{{cite book |last=Wittig |first=Jörg |editor=H. J. Queisser |date=1973 |title=Festkörper Probleme: Plenary Lectures of the Divisions Semiconductor Physics, Surface Physics, Low Temperature Physics, High Polymers, Thermodynamics and Statistical Mechanics, of the German Physical Society, Münster, March 19–24, 1973 |chapter=The pressure variable in solid state physics: What about 4f-band superconductors? |series=Advances in Solid State Physics |volume=13 |location=Berlin, Heidelberg |publisher=Springer |pages=375–396 |isbn=978-3-528-08019-8 |doi=10.1007/BFb0108579}}</ref><ref name=Matthias>{{cite book |last=Matthias |first=B. T. |date=1969 |editor-last=Wallace |editor-first=P. R. |title=Superconductivity |publisher=Gordon and Breach |pages=225–294 <!--precise quote calling it a mistake is on pp. 247–9--> |chapter=Systematics of Super Conductivity |isbn=9780677138107 |volume=1}}</ref> this is the classification adopted by most chemists and physicists who have considered the matter.<ref name=Jensen2015/> It was supported by IUPAC in a 1988 report<ref name=Fluck/> and reaffirmed in 2021.<ref name=2021IUPAC/> Many textbooks however show group 3 as containing scandium, yttrium, lanthanum, and actinium, a format based on historically wrongly measured electron configurations:<ref name=Jensen1982/> [[Lev Landau]] and [[Evgeny Lifshitz]] already considered it to be "incorrect" in 1948,<ref name=Landau/> but the issue was brought to a wide debate only in 1982 by [[William B. Jensen]].<ref name="Jensen1982"/>

The spaces below yttrium are sometimes left blank as a third option, but there is confusion in the literature on whether this format implies that group 3 contains only scandium and yttrium, or if it also contains all the lanthanides and actinides;<ref name=2021IUPAC/><ref name=Thyssen/><ref name="JWP">{{cite journal |author=Barber, Robert C. |author2=Karol, Paul J |author3=Nakahara, Hiromichi |author4=Vardaci, Emanuele |author5=Vogt, Erich W. |title=Discovery of the elements with atomic numbers greater than or equal to 113 (IUPAC Technical Report) |doi=10.1351/PAC-REP-10-05-01 |journal=Pure Appl. Chem. |date=2011 |volume=83 |issue=7 |page=1485|doi-access=free }}</ref><ref name="Karol">{{cite journal |last1=Karol |first1=Paul J. |last2=Barber |first2=Robert C. |last3=Sherrill |first3=Bradley M. |last4=Vardaci |first4=Emanuele |last5=Yamazaki |first5=Toshimitsu |date=22 December 2015 |title=Discovery of the elements with atomic numbers Z = 113, 115 and 117 (IUPAC Technical Report) |journal=Pure Appl. Chem. |volume=88 |issue=1–2 |pages=139–153 |doi=10.1515/pac-2015-0502|doi-access=free }}</ref><ref>{{cite journal |last1=Pyykkö |first1=Pekka |date=2019 |title=An essay on periodic tables |url=http://www.chem.helsinki.fi/~pyykko/pekka/No330b.pdf |journal=Pure and Applied Chemistry |volume=91 |issue=12 |pages=1959–1967 |doi=10.1515/pac-2019-0801 |s2cid=203944816 |access-date=27 November 2022}}</ref> either way, this format contradicts quantum physics by creating a 15-element-wide f-block when only 14 electrons can fit in an f-subshell.<ref name=2021IUPAC/> While the 2021 IUPAC report noted that 15-element-wide f-blocks are supported by some practitioners of a specialised branch of [[relativistic quantum mechanics]] focusing on the properties of [[superheavy element]]s, the project's opinion was that such interest-dependent concerns should not have any bearing on how the periodic table is presented to "the general chemical and scientific community".<ref name=2021IUPAC/> In fact, relativistic quantum-mechanical calculations of Lu and Lr compounds found no valence f-orbitals in either element.<ref name=XuPyykko>{{cite journal |last1=Xu |first1=Wen-Hua |last2=Pyykkö |first2=Pekka |date=8 June 2016 |url=http://pubs.rsc.org/-/content/articlehtml/2016/cp/c6cp02706g |title=Is the chemistry of lawrencium peculiar |journal=Phys. Chem. Chem. Phys. |volume=2016 |issue=18 |pages=17351–5 |doi=10.1039/c6cp02706g |pmid=27314425 |access-date=24 April 2017|bibcode=2016PCCP...1817351X |hdl=10138/224395 |s2cid=31224634 |hdl-access=free }}</ref> Other authors focusing on superheavy elements since clarified that the "15th entry of the f-block represents the first slot of the d-block which is left vacant to indicate the place of the f-block inserts", which would imply that this form still has Lu and Lr (the 15th entries in question) as d-block elements under Sc and Y.<ref name=smits>{{cite journal |last1=Smits |first1=Odile R. |last2=Düllmann |first2=Christoph E. |last3=Indelicato |first3=Paul |last4=Nazarewicz |first4=Witold |last5=Schwerdtfeger |first5=Peter |date=2023 |title=The quest for superheavy elements and the limit of the periodic table |url= |journal=Nature Reviews Physics |volume= 6|issue= 2|pages= 86–98|doi=10.1038/s42254-023-00668-y |s2cid=266276980 |access-date=}}</ref> Indeed, when IUPAC publications expand the table to 32 columns, they make this clear and place Lu and Lr under Y.<ref>{{cite journal |last1=Leigh |first1=G. Jeffrey |date=2009 |title=Periodic Tables and IUPAC |url=https://publications.iupac.org/ci/2009/3101/1_leigh.html |journal=Chemistry International |volume=31 |issue=1 |pages=4–6 |doi=10.1515/ci.2009.31.1.4 |access-date=8 January 2024}}</ref><ref>{{cite book |editor-last=Leigh |editor-first=G. Jeffrey |date=1990 |title=Nomenclature of inorganic chemistry : recommendations 1990 |url=https://archive.org/details/nomenclatureofin0000unse/page/282/mode/2up |location= |publisher=Blackwell Scientific Publications |page=283 |isbn=0-632-02319-8}}</ref>

As noted by the 2021 IUPAC report, Sc-Y-Lu-Lr is the only form that simultaneously allows for the preservation of the sequence of atomic number, avoids splitting the d-block into "two highly uneven portions", and gives the blocks the correct widths quantum mechanics demands (2, 6, 10, and 14).<ref name="2021IUPAC">{{cite journal |last1=Scerri |first1=Eric |date=18 January 2021 |title=Provisional Report on Discussions on Group 3 of the Periodic Table |url=https://iupac.org/wp-content/uploads/2021/04/ChemInt_Jan2021_PP.pdf |journal=Chemistry International |volume=43 |issue=1 |pages=31–34 |doi=10.1515/ci-2021-0115 |s2cid=231694898 |access-date=9 April 2021 |archive-date=13 April 2021 |archive-url=https://web.archive.org/web/20210413150110/https://iupac.org/wp-content/uploads/2021/04/ChemInt_Jan2021_PP.pdf |url-status=live }}</ref> While arguments in favour of Sc-Y-La-Ac can still be found in the literature, many authors consider them to be logically inconsistent.<ref name=Jensen1982/><ref name=Jensen2015/> For example, it has been argued that lanthanum and actinium cannot be f-block elements because their atoms have not begun to fill the f-subshells.<ref name=Lavelle>{{cite journal |last1=Lavelle |first1=Laurence |date=2008 |title=Lanthanum (La) and Actinium (Ac) Should Remain in the d-block |journal=Journal of Chemical Education |volume=85 |issue=11 |pages=1482–1483 |doi=10.1021/ed085p1482|bibcode=2008JChEd..85.1482L |doi-access=free }}</ref> But the same is true of thorium which is never disputed as an f-block element,<ref name=2021IUPAC/><ref name=Jensen1982/> and this argument overlooks the problem on the other end: that the f-shells complete filling at ytterbium and nobelium (matching the Sc-Y-Lu-Lr form), not at lutetium and lawrencium (as in Sc-Y-La-Ac).<ref name=johnson>{{cite book |last=Johnson |first=David |author-link= |date=1984 |title=The Periodic Law |url=https://www.rsc.org/images/23_The_Periodic_Law_tcm18-30005.pdf |location= |publisher=The Royal Society of Chemistry |page= |isbn=0-85186-428-7}}</ref> Lanthanum, actinium, and thorium are simply examples of exceptions to the [[Aufbau principle#Madelung energy ordering rule|Madelung rule]]; not only do those exceptions represent a minority of elements (only 20 out of 118),<ref name=johnson/> but they have also never been considered as relevant for positioning any other elements on the periodic table. In gaseous atoms, the d-shells complete their filling at copper (3d<sup>10</sup>4s<sup>1</sup>), palladium (4d<sup>10</sup>5s<sup>0</sup>), and gold (5d<sup>10</sup>6s<sup>1</sup>), but it is universally accepted by chemists that these configurations are exceptional and that the d-block really ends in accordance with the Madelung rule at zinc (3d<sup>10</sup>4s<sup>2</sup>), cadmium (4d<sup>10</sup>5s<sup>2</sup>), and mercury (5d<sup>10</sup>6s<sup>2</sup>).<ref name="Thyssen">{{cite book|last1=Thyssen|first1=P.|last2=Binnemans|first2=K.|editor1-last=Gschneidner|editor1-first= K. A. Jr.|editor2-last=Bünzli|editor2-first=J-C.G|editor3-last=Vecharsky|editor3-first=Bünzli|date=2011|title=Accommodation of the Rare Earths in the Periodic Table: A Historical Analysis|journal=Handbook on the Physics and Chemistry of Rare Earths|publisher=Elsevier|location=Amsterdam|volume=41|pages=1–94|isbn=978-0-444-53590-0|doi=10.1016/B978-0-444-53590-0.00001-7}}</ref> The relevant fact for placement is that lanthanum and actinium (like thorium) have valence f-orbitals that can become occupied in chemical environments, whereas lutetium and lawrencium do not:<ref name=Wittig/><ref name=jensenlaw/> their f-shells are in the core, and cannot be used for chemical reactions.<ref>{{cite book |last=Wulfsberg |first=Gary |author-link= |date=2000 |title=Inorganic Chemistry |url= |location= |publisher=University Science Books |page=26 |isbn=9781891389016}}</ref><ref>{{cite journal | last1=Krinsky | first1=Jamin L. | last2=Minasian | first2=Stefan G. | last3=Arnold | first3=John | title=Covalent Lanthanide Chemistry Near the Limit of Weak Bonding: Observation of (CpSiMe<sub>3</sub>)<sub>3</sub>Ce−ECp* and a Comprehensive Density Functional Theory Analysis of Cp<sub>3</sub>Ln−ECp (E = Al, Ga) | journal=Inorganic Chemistry | publisher=American Chemical Society (ACS) | volume=50 | issue=1 | date=2010-12-08 | issn=0020-1669 | doi=10.1021/ic102028d | pages=345–357| pmid=21141834 }}</ref> Thus the relationship between yttrium and lanthanum is only a secondary relationship between elements with the same number of valence electrons but different kinds of valence orbitals, such as that between chromium and uranium; whereas the relationship between yttrium and lutetium is primary, sharing both valence electron count and valence orbital type.<ref name=jensenlaw>{{cite web|url=http://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/081.%20Periodic%20Table.pdf|last1=Jensen|first1=William B.|authorlink=William B. Jensen|title=The Periodic Law and Table|date=2000|archive-url=https://web.archive.org/web/20201110113324/http://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/081.%20Periodic%20Table.pdf |access-date=10 December 2022|archive-date=2020-11-10 }}</ref>