Occasionally, even the group 3 elements as well as the lanthanides and actinides have been included, because especially the group 3 elements and lanthanides are electropositive elements with only one main oxidation state like the group 1 and 2 elements.
Kadang-kadang, bahkan unsur-unsur golongan 3 serta lantanida dan aktinida juga disertakan, karena terutama unsur golongan 3 dan lantanida adalah unsur elektropositif dengan hanya satu keadaan oksidasi utama seperti unsur golongan 1 dan 2.