Ionization potential is one of the most important terms in the study of atomic structures. It refers to the energy required to remove an electron from an atom or molecule. There are several synonyms for this term, including ionization energy, electron affinity, and ionization potential energy. Ionization energy is often used interchangeably with ionization potential, but it specifically refers to the amount of energy required to remove an electron from a gaseous atom or ion in its ground state. Electron affinity, on the other hand, is the energy released when an electron is added to a neutral atom or molecule. Finally, ionization potential energy is simply a more specific way of referring to the amount of energy required to remove an electron from an atom or molecule.