Fluorine and iodine belong to which group of elements?

Fluorine and iodine are classified as halogens, which are located in Group 17 of the periodic table. The halogens are known for their high reactivity, particularly with alkali and alkaline earth metals, forming various compounds such as salts. This group consists of nonmetals that commonly exist as diatomic molecules in their elemental forms (F2 for fluorine and I2 for iodine). They have similar chemical properties due to their similar electron configurations, specifically having seven electrons in their outermost shell, which drives their reactivity in forming bonds by gaining or sharing one additional electron.

The other groups listed have distinct characteristics: noble gases (Group 18) are generally inert and do not readily form compounds; chalcogens (Group 16) include elements like oxygen and sulfur, which have different reactivity patterns; and alkaline earth metals (Group 2) are metals that are quite different from the nonmetals in the halogen group. Hence, the classification of fluorine and iodine as halogens is accurate and reflects their chemical behavior in the periodic table.