Editing Group 3 element (section)

===Physical===
The trends in group 3 follow those of the other early d-block groups and reflect the addition of a filled f-shell into the core in passing from the fifth to the sixth period. For example, scandium and yttrium are both soft metals. But because of the [[lanthanide contraction]], the expected increase in atomic radius from yttrium to lutetium is reversed; lutetium atoms are slightly smaller than yttrium atoms, but are heavier and have a higher nuclear charge.<ref>{{cite journal |last1=Chistyakov |first1=V. M. |date=1968 |title=Biron's Secondary Periodicity of the Side d-subgroups of Mendeleev's Short Table |url=https://archive.org/details/sim_russian-journal-of-general-chemistry_1968-02_38_2/page/212/mode/2up |journal=Journal of General Chemistry of the USSR |volume=38 |issue=2 |pages=213–214 |doi= |access-date=6 January 2024}}</ref><ref name="r"/> This makes the metal more dense, and also harder because the extraction of the electrons from the atom to form [[metallic bonding]] becomes more difficult. All three metals have similar melting and boiling points.<ref name="n"/> Very little is known about lawrencium, but calculations suggest it continues the trend of its lighter congeners toward increasing density.<ref name=Lrdensity>{{cite journal |last=Fournier |first=Jean-Marc |date=1976 |title=Bonding and the electronic structure of the actinide metals |journal=Journal of Physics and Chemistry of Solids |volume=37 |issue=2 |pages=235–244 |doi=10.1016/0022-3697(76)90167-0|bibcode=1976JPCS...37..235F }}</ref><ref name=Penneman>{{cite journal |last1=Penneman |first1=R. A. |last2=Mann |first2=J. B. |date=1976 |title='Calculation chemistry' of the superheavy elements; comparison with elements of the 7th period |journal=Proceedings of the Moscow Symposium on the Chemistry of Transuranium Elements |pages=257–263 |doi=10.1016/B978-0-08-020638-7.50053-1 |isbn=978-0-08-020638-7 }}</ref>

Scandium, yttrium, and lutetium all crystallize in the [[hexagonal close-packed]] structure at room temperature,<ref name=Greenwood946>Greenwood and Earnshaw, pp. 946–8</ref> and lawrencium is expected to do the same.<ref name=hcp>{{cite journal|doi=10.1103/PhysRevB.84.113104|title=First-principles calculation of the structural stability of 6d transition metals|year=2011|last1=Östlin|first1=A.|last2=Vitos|first2=L.|journal=Physical Review B|volume=84|issue=11|page=113104|bibcode=2011PhRvB..84k3104O }}</ref> The stable members of the group are known to change structure at high temperature. In comparison with most metals, they are not very good conductors of heat and electricity because of the low number of electrons available for metallic bonding.<ref name=Greenwood946/>
{| class="wikitable centered" style="text-align:center;"
|+Properties of the group 3 elements| Properties of the group 3 elements<ref>{{cite book | editor = Lide, D. R. | title = CRC Handbook of Chemistry and Physics | edition = 84th | location = Boca Raton, FL | publisher = CRC Press | year = 2003 }}</ref>
! Name
! Sc, [[scandium]]
! Y, [[yttrium]]
! Lu, [[lutetium]]
! Lr, [[lawrencium]]
|-
| style="background:lightgrey; text-align:left;"|[[Melting point]]<ref name="nn">{{cite web|last = Barbalace|first = Kenneth|url = http://environmentalchemistry.com/yogi/periodic/meltingpoint.html|title = Periodic Table of Elements Sorted by Melting Point|publisher = Environmental Chemistry.com|access-date = 2011-05-18}}</ref>
| 1814&nbsp;K, 1541&nbsp;°C || 1799&nbsp;K, 1526&nbsp;°C || 1925&nbsp;K, 1652&nbsp;°C || 1900&nbsp;K, 1627&nbsp;°C
|-
|style="background:lightgrey; text-align:left;"|[[Boiling point]]<ref name="n">{{cite web|last = Barbalace|first = Kenneth|url = http://environmentalchemistry.com/yogi/periodic/boilingpoint.html|title = Periodic Table of Elements Sorted by Boiling Point|publisher = Environmental Chemistry.com|access-date = 2011-05-18}}</ref>
| 3109&nbsp;K, 2836&nbsp;°C || 3609&nbsp;K, 3336&nbsp;°C || 3675&nbsp;K, 3402&nbsp;°C || ?
|-
| style="background:lightgrey; text-align:left;"|[[Density]]
| 2.99&nbsp;g·cm<sup>−3</sup> || 4.47&nbsp;g·cm<sup>−3</sup> || 9.84&nbsp;g·cm<sup>−3</sup> || ? 14.4&nbsp;g·cm<sup>−3</sup>
|-
| style="background:lightgrey; text-align:left;"|Appearance
| silver metallic || silver white || silver gray || ?
|-
| style="background:lightgrey; text-align:left;"|[[Atomic radius]]<ref name="r">{{cite book |last=Dean |first=John A. |title=Lange's handbook of chemistry |publisher=McGraw-Hill, Inc|year=1999|pages=589–592|isbn=0-07-016190-9|edition=Fifteenth }}</ref>
| 162 pm || 180 pm || 174 pm || ?
|}