F⁻ is the fluoride ion—an anion that carries a net negative charge due to gaining one electron and forming from the dissociation of HF in water.
Cl⁻: This term represents the chloride ion—a negatively charged anion formed when chlorine gains one electron.
Br⁻: This term refers to bromide ion—an anion created when bromine accepts one additional electron.
I⁻: This term stands for iodide—the negatively charged anion formed by iodine accepting one extra electron.