Editing Group 3 element (section)

===Chemical===

{| class="wikitable" style="float:right; font-size:95%;white-space:nowrap;"
|+
! colspan=4 | [[Electron configuration]]s of the group 3 elements
|-
! {{abbr|1=''Z''|2=Atomic number}} !! Element !! Electrons per [[Electron shell|shell]] !! Electron configuration
|-
| style="text-align:right" | 21 || Sc, scandium || {{mono|2, 8, &nbsp;9, &nbsp;2}}    || {{mono|1=[Ar] &nbsp;&nbsp;<sup>&nbsp;&nbsp;</sup> 3d<sup>1</sup> 4s<sup>2</sup>}}
|-
| style="text-align:right" | 39 || Y, yttrium   || {{mono|2, 8, 18, &nbsp;9, &nbsp;2}}|| {{mono|1=[Kr] &nbsp;&nbsp;<sup>&nbsp;&nbsp;</sup> 4d<sup>1</sup> 5s<sup>2</sup>}}
|-
| style="text-align:right" | 71 || Lu, lutetium || {{mono|2, 8, 18, 32, &nbsp;9, 2}}  || {{mono|1=[Xe] 4f<sup>14</sup> 5d<sup>1</sup> 6s<sup>2</sup>}}
|-
| style="text-align:right" | 103 || Lr, lawrencium || {{mono|2, 8, 18, 32, 32, 8, 3}} || {{mono|1=[Rn] 5f<sup>14</sup> 6d<sup>0</sup> 7s<sup>2</sup> 7p<sup>1</sup>}}
|}
Like other groups, the members of this family show patterns in their electron configurations, especially the outermost shells, resulting in trends in chemical behavior. Due to [[Relativistic quantum chemistry|relativistic effects]] that become important for high atomic numbers, lawrencium's configuration has an irregular 7p occupancy instead of the expected 6d,<ref name="7p">{{cite journal |last1 = Eliav|first1 = E.|last2=Kaldor|first2=U.|last3=Ishikawa|first3=Y. |title = Transition energies of ytterbium, lutetium, and lawrencium by the relativistic coupled-cluster method |journal = [[Physical Review|Phys. Rev. A]]|volume = 52|issue = 1|pages = 291–296 |year = 1995 |doi = 10.1103/PhysRevA.52.291|pmid = 9912247|bibcode = 1995PhRvA..52..291E }}</ref><ref name="7p1/2">{{cite journal|last1 = Zou|first1 = Yu|last2=Froese|first2=Fischer C. |title = Resonance Transition Energies and Oscillator Strengths in Lutetium and Lawrencium|journal = [[Physical Review Letters|Phys. Rev. Lett.]] |volume = 88|page = 183001|year = 2002|pmid=12005680|issue=18|bibcode = 2001PhRvL..88b3001M |doi = 10.1103/PhysRevLett.88.023001 | s2cid=18391594 |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1011&context=physicsuiterwaal|url-access = subscription}}</ref> but the regular [Rn]5f<sup>14</sup>6d<sup>1</sup>7s<sup>2</sup> configuration is low enough in energy that no significant difference from the rest of the group is observed or expected.<ref name="JensenLr">{{cite web|url=https://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/251.%20Lawrencium.pdf |title=Some Comments on the Position of Lawrencium in the Periodic Table |last1=Jensen |first1=W. B. |date=2015 |access-date=20 September 2015 |url-status=dead |archive-url=https://web.archive.org/web/20151223091325/https://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/251.%20Lawrencium.pdf |archive-date=23 December 2015 }}</ref><ref name=Xu>{{cite journal |last1=Xu |first1=W-H. |last2= Pyykkö|first2=P.|title=Is the chemistry of lawrencium peculiar? |journal=Physical Chemistry Chemical Physics |year=2016 |volume=18 |issue=26 |pages=17351–17355|doi=10.1039/C6CP02706G|pmid=27314425 |bibcode=2016PCCP...1817351X|hdl=10138/224395 |s2cid=31224634 |url=https://helda.helsinki.fi/bitstream/10138/224395/1/c6cp02706g.pdf |hdl-access=free }}</ref>

Most of the chemistry has been observed only for the first three members of the group; chemical properties of lawrencium are not well-characterized, but what is known and predicted matches its position as a heavier homolog of lutetium. The remaining elements of the group (scandium, yttrium, lutetium) are quite electropositive. They are reactive metals, although this is not obvious due to the formation of a stable oxide layer which prevents further reactions. The metals burn easily to give the oxides,<ref name=Greenwood964>Greenwood and Earnshaw, pp. 964–5</ref> which are white high-melting solids. They are usually oxidized to the +3 oxidation state, in which they form mostly ionic compounds and have a mostly cationic aqueous chemistry. In this way they are similar to the lanthanides,<ref name=Greenwood964/> although they lack the involvement of f orbitals that characterises the chemistry of the 4f elements lanthanum through ytterbium.<ref>{{cite journal |last1=Wang |first1=Fan |last2=Le-Min |first2=Li |date=2002 |title=镧系元素 4f 轨道在成键中的作用的理论研究 |trans-title=Theoretical Study on the Role of Lanthanide 4f Orbitals in Bonding |language=zh |journal=Acta Chimica Sinica |volume=62 |issue=8 |pages=1379–84}}</ref><ref name=LaF3>{{cite journal |last1=Xu |first1=Wei |last2=Ji |first2=Wen-Xin |first3=Yi-Xiang |last3=Qiu |first4=W. H. Eugen |last4=Schwarz |first5=Shu-Guang |last5=Wang |date=2013 |title=On structure and bonding of lanthanoid trifluorides LnF<sub>3</sub> (Ln = La to Lu) |journal=Physical Chemistry Chemical Physics |volume=2013 |issue=15 |pages=7839–47 |doi=10.1039/C3CP50717C|pmid=23598823 |bibcode=2013PCCP...15.7839X }}</ref> The stable group 3 elements are thus often grouped with the 4f elements as the so-called [[rare-earth element|rare earths]].<ref name=Greenwood964/>

Typical transition-metal properties are mostly absent from this group, as they are for the heavier elements of groups 4 and 5: there is only one typical oxidation state and the coordination chemistry is not very rich (though high coordination numbers are common due to the large size of the M<sup>3+</sup> ions). This said, low-oxidation state compounds may be prepared and some [[Cyclopentadienyl complex|cyclopentadienyl]] chemistry is known. The chemistries of group 3 elements are thus mostly distinguished by their atomic radii:<ref name=Greenwood964/> yttrium and lutetium are very similar,<ref>''The Heavy Transition Metals'', p. 3</ref> but scandium stands out as the least basic and the best complexing agent, approaching [[aluminium]] in some properties.<ref name=Greenwood964/> They naturally take their places together with the rare earths in a series of trivalent elements: yttrium acts as a rare earth intermediate between [[dysprosium]] and [[holmium]] in basicity; lutetium as less basic than the 4f elements and the least basic of the lanthanides; and scandium as a rare earth less basic than even lutetium.<ref name=Jorgensen>{{cite book |last=Jørgensen |first=Christian K. |date=1988 |title=Handbook on the Physics and Chemistry of Rare Earths |volume=11 |chapter=Influence of rare earths on chemical understanding and classification |pages=197–292 |doi=10.1016/S0168-1273(88)11007-6|isbn=9780444870803 }}</ref> Scandium oxide is [[amphoterism|amphoteric]]; lutetium oxide is more basic (although it can with difficulty be made to display some acidic properties), and yttrium oxide is more basic still.<ref>{{cite book|first=S. A.|last=Cotton|chapter=Scandium, Yttrium and the Lanthanides: Inorganic and Coordination Chemistry|title=Encyclopedia of Inorganic Chemistry|year=1994|publisher=John Wiley & Sons|isbn=0-471-93620-0}}</ref> Salts with strong acids of these metals are soluble, whereas those with weak acids (e.g. fluorides, phosphates, oxalates) are sparingly soluble or insoluble.<ref name=Greenwood964/>