Atoms and Elements 1

There were two accepted systems of numbering the periodic table, one of which called the noble gasses group VIIIA, often changed informally to group 8 (most commonly used in the USA) and the other that called it group 0 (most commonly used in Europe). The naming of anything in chemistry now is governed by a single organization IUPAC (International Union of Pure and Applied Chemistry) and they have simplified the group numbering so the noble gasses have now become group 18. Groups are also often referred to by the name of the first element in the group - the noble gasses could also be called the helium group.

Other than groups 1 and 2, all of the other group numbers have changed for example the halogens are no longer officially group 7, they are group 17. At the moment, many school text books still refer to the groups by their old numbers and names though some schools (maybe even yours) may already have changed.