👉 In the context of quantum mechanics, an "ionic" system is a physical system in which electrons are distributed within a nucleus. The electron distribution can be described by an ionization potential or a charge density. For example, consider a hydrogen atom where there's only one electron, and it has a positive charge (1 eV). If the electron is in an excited state (like n=2), its energy will be less than 1 eV. This means that the nucleus has lost