Halogens Group 7A; very reactive non-metals; gain 1 valence electron to become negatively charged

Group 2A; slightly less reactive metals; lose their 2 valence electrons to become positively charged

Group 8A; non-reactive non-metals; do not lose or gain valence electrons, because they already have 2 or 8 valence electrons

Group 1A; very reactive metals; lose their 1 valence electron to become positively charged