Final answer:
Group I elements (alkali metals) react with Group VII elements (halogens) to form stable ionic bonds by transferring an electron from the metal to the halogen, resulting in a one-to-one ratio of ions.
Step-by-step explanation:
The elements in Group I, also known as the alkali metals, would react most favorably with the elements in Group VII (Group 17) to form stable ionic bonds with no subscripts, meaning just one atom of each element. This is because alkali metals have one loosely bound s electron in their outer shell, making them ready to lose that electron and form a positively charged ion.
Halogens, found in Group VII, have one vacancy in their p outer shell, and they readily accept an extra electron to form negatively charged ions. Therefore, the reaction between these two groups would produce compounds with a one-to-one ratio of ions, resulting in stable ionic bonds.