Editing Periodic table (section)

=== Group names and numbers ===
Under an international naming convention, the groups are numbered numerically from 1 to 18 from the leftmost column (the alkali metals) to the rightmost column (the noble gases). The f-block groups are ignored in this numbering.<ref name="IUPAC">{{cite book|title=Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005|last1=Connelly|first1=N. G.|last2=Damhus|first2=T.|last3=Hartshorn|first3=R. M.|last4=Hutton|first4=A. T.|year=2005|publisher=RSC Publishing|isbn=978-0-85404-438-2|page=51|url=https://old.iupac.org/publications/books/rbook/Red_Book_2005.pdf|access-date=26 November 2018|archive-url=https://web.archive.org/web/20181123034019/https://old.iupac.org/publications/books/rbook/Red_Book_2005.pdf|archive-date=23 November 2018|url-status=live}}</ref> Groups can also be named by their first element, e.g. the "scandium group" for group 3.<ref name="IUPAC"/> Previously, groups were known by [[Roman numerals]]. In the United States, the Roman numerals were followed by either an "A" if the group was in the [[s-block|s-]] or [[p-block]], or a "B" if the group was in the [[d-block]]. The Roman numerals used correspond to the last digit of today's naming convention (e.g. the [[group 4 element]]s were group IVB, and the [[Carbon group|group 14 elements]] were group IVA). In Europe, the lettering was similar, except that "A" was used for groups 1 through 7, and "B" was used for groups 11 through 17. In addition, groups 8, 9 and 10 used to be treated as one triple-sized group, known collectively in both notations as group VIII. In 1988, the new [[IUPAC]] (International Union of Pure and Applied Chemistry) naming system (1–18) was put into use, and the old group names (I–VIII) were deprecated.<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>

{{Periodic table (group names)}}