An iodide is a negatively charged ion composed of a single iodine atom. It's often formed when an iodine atom gains one electron.
A chemical element in the halogen group that can gain an electron to form an iodide ion.
A negatively charged ion, like the iodide.
The amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion, such as in the formation of an iodide.