What type of ions do halogens form when they react with metals?

Halogens, which are elements found in Group 17 of the periodic table, typically gain electrons when they react with metals. This process occurs because halogens have seven valence electrons and need one more to achieve a full outer shell, satisfying the octet rule. By gaining an electron, halogens become negatively charged ions, known as anions.

When halogens react with metals, they form these negative ions primarily because metals tend to lose electrons easily, becoming positively charged ions (cations). The resulting ionic bond is formed due to the electrostatic attraction between the positively charged metal ions and the negatively charged halide ions.

This characteristic behavior of halogens is a key aspect of their reactivity and is fundamental in understanding ionic compounds formed between metals and nonmetals. The other options do not accurately reflect the behavior of halogens in such reactions: metals do not form positive ions when reacting with halogens, nor do they retain their neutral atomic state in this interaction. Additionally, radical ions, which contain an unpaired electron, typically involve different conditions and reactions than those associated with halogen-metal interactions.