In the periodic table which elements typically have similar properties

Elements which appear in the same column have similar properties (periodicity). For example, all of the elements in group XVII (17), the Halogens, all react in a similar fashion; they all like to attract one additional electron and form a -1 anion.

Outermost (valence) electrons

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is