Upon completion of this module, you should be able to understand how ionic bonds form and what type of attraction the bonds consist of and define cation and anion. An ionic bond forms when one atom transfers a valence electron to another atom. Valence electrons are the electrons furthest away from the nucleus in an atom. The electron donor is usually metal, and the recipient is typically a nonmetal. The more electronegative atom is generally the recipient of the electron. Electronegativity is a measure of the extent to which an atom attracts electrons.