What is a halogenide?

A halogenide refers to an ion formed when a halogen, which is a member of Group 17 in the periodic table (such as fluorine, chlorine, bromine, iodine, and astatine), gains an electron to achieve a complete octet, forming negatively charged ions known as halides. These halides can then combine with metal ions to form halides, which are compounds comprised of metal cations and halide anions.

For instance, when sodium (a metal) reacts with chlorine (a halogen), it forms sodium chloride (NaCl), where the sodium ion (Na⁺) and the chloride ion (Cl⁻) are held together by ionic bonds. This demonstrates the fundamental nature of halogenide formation involving an interaction between a metal and a halogen.

The other choices do not accurately define halogenides. Compounds formed solely from metals are not considered halogenides, as they lack the essential halogen component. While some halogenides may exist as gases at room temperature, this is not a defining characteristic as many halogenides are solid or liquid. Additionally, halogenides are not specifically classified as acids, which are substances that can donate protons (H⁺ ions)