________ are highly reactive nonmetals that occupy group 17 of the periodic table. Fluorine, chlorine, and iodine are examples.

• A. Halogens
• B. Noble Gases
• C. Alkali Metals
• D. Transition Metals

Answer: (A)

Group 17 contains halogens, a family of highly reactive nonmetals. They all have seven valence electrons, so they eagerly gain one electron to complete their outer shell. That drive to achieve a full octet makes them extremely reactive, especially with metals to form salts. They also have high electronegativity, meaning they attract electrons strongly in bonds. In their elemental form, they exist as diatomic molecules such as F2 and Cl2. Among them, reactivity is highest for fluorine and decreases as you move down the group toward iodine, because increasing atomic size and shielding weaken the attraction for added electrons. Fluorine, chlorine, and iodine are classic examples of this family.