Final answer:
The trend in reactivity for elements on the right side of the periodic table is that nonmetals tend to gain electrons in chemical reactions, with fluorine being the most reactive nonmetal. Metals in groups 1 and 2, on the other hand, have increasing reactivity down a group.
Step-by-step explanation:
The trend in reactivity for elements on the right side of the periodic table (excluding noble gases) is that nonmetals tend to gain electrons in chemical reactions and have a high attraction for electrons within a compound. The most reactive nonmetal is fluorine, which is not found in nature as a free element and reacts explosively with many other elements and compounds. On the other hand, the reactivity of metals in groups 1 and 2 increases down a group due to the ease of losing the lone valence electron.