Ionelectrons

Ionelectrons is a term used to describe the electrons that are bound to an ion, i.e., the electronic complement of a charged species formed by ionization. In this sense, an ion's electrons include both core and, where present, valence electrons that remain associated with the ion after one or more electrons have been removed or added.

Formation and structure: Ions arise by ionization (removal of electrons) or association (addition of electrons) to neutral atoms. The resulting ion possesses an electron configuration determined by the net charge and the effective nuclear charge, often described by term symbols and energy levels that differ from the neutral atom. Because electron–electron repulsion and spin–orbit coupling modify energy levels, the spectra of ions can be markedly different from those of neutral atoms.

Properties and roles: The distribution and energies of ion electrons influence the chemical behavior of the ion, its spectral lines, and its interactions with electromagnetic fields. In plasmas and ionic solids, ion electrons are distinguished from free electrons, which move more or less independently and contribute to conductivity and screening differently.

Measurement and applications: Techniques such as photoelectron spectroscopy and X-ray spectroscopy probe the binding energies and configurations of ion electrons. Understanding ion electrons is essential in fields ranging from astrophysics and plasma physics to materials science and catalysis.

Etymology and context: The term is not standard across all disciplines and may appear in introductory discussions of electronic structure to emphasize the distinction between bound ion electrons and free electrons. See also electron, ion, ionization, spectroscopy.