1. having the same number of electrons, especially referring to atoms or ions with identical electron configurations
Usage: chemistry and physics term; commonly used in atomic and molecular structure discussions

Examples

• Sodium ions and neon atoms are isoelectronic, both having 10 electrons.
• The chloride ion and argon are isoelectronic species.
• Isoelectronic ions often have similar chemical properties despite different nuclear charges.
• In the isoelectronic series, the effective nuclear charge increases as the atomic number increases.
• Oxygen and fluorine ions can be isoelectronic with neon.