Group (periodic table)

A periodic table group is a vertical column in the periodic table of the elements.

It is no accident that many of these correspond to chemical series: the periodic table was originally created to organize the known chemical series into a single coherent scheme.

There are two ways of numbering the groups of the periodic table, one using Roman numerals and the other using Arabic numerals.

The Roman numeral names are the original traditional names of the groups; the Arabic numeral names are those recommended by IUPAC to replace the old names.

Note: There was also an old system in use that combined the use of Roman numerals with letters: the IUPAC scheme was developed to replace this system as it was confusing, with two different versions in use in different parts of the world. Wikipedia style should be to replace the old names of the groups with the new IUPAC names throughout, with a historical mention of the old name where appropriate.

The periodic table groups are as follows:

Group 1 (Roman numbering I): the Alkali metals
Group 2 (Roman numbering II): the Alkaline earth metals
Group 3
Group 4
Group 5
Group 6
Group 7
Group 8
Group 9
Group 10
Group 11: the Coinage metals
Group 12
Group 13 (Roman numbering III)
Group 14 (Roman numbering IV)
Group 15 (Roman numbering V)
Group 16 (Roman numbering VI): the Chalcogens
Group 17 (Roman numbering VII): the Halogens
Group 18 (Roman numbering VIII): the Noble gases