1. Having the same number of atoms or the same number of valence electrons; relating to compounds or ions with identical electron configurations.
Usage: chemistry; technical

Examples

• Carbon monoxide and nitrogen are isosteric molecules because they both have 14 electrons.
• The isosteric relationship between CO and N₂ explains some of their similar chemical properties.
• Chemists use isosteric substitution to design drugs with improved properties.
• Methane and ammonia are not isosteric because they have different numbers of electrons.
• In medicinal chemistry, isosteric replacements can help reduce toxicity while maintaining efficacy.