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Isoelectronic

Quick Reference
Also Known AsIsoelectronic species, isoelectronic analogy, iso-valence electronic

What is Isoelectronic?

Describes atoms, ions, or molecules that have the same number of electrons and the same electronic configuration. For example, N³⁻, O²⁻, F⁻, Ne, Na⁺, Mg²⁺, and Al³⁺ are all isoelectronic with 10 electrons. Isoelectronic species often have similar properties.

Properties & Characteristics

Isoelectronic species have the same number of electrons and the same electronic structure (bonding arrangement), though they differ in nuclear charges. Examples: N₂ and CO (both 14e⁻, triple bond); NO⁺ and CO; CO₂ and N₂O? (different structure) — N₂O and CO₂ are isoelectronic by electron count only. Isoelectronic species often have similar shapes, bond orders, and properties. The isoelectronic principle is widely used in inorganic and organometallic chemistry.

Uses & Applications

Isoelectronic relationships are used to predict properties of unknown species by analogy to known ones: CF₄ and SiF₄ (both tetrahedral, Group 14), BF₄⁻ and NH₄⁺ (both tetrahedral, same 32e⁻). CO is used as an isoelectronic analogy to N₂ in rationalising its binding to haemoglobin (similar to O₂ binding site).

Safety Information

CO's toxicity is partly rationalised by its isoelectronic relationship with N₂ and similarity to O₂ in binding to haem iron — CO binds 200× more strongly than O₂. Understanding isoelectronic analogies helps predict toxicity and reactivity of related species.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Isoelectronic
Synonyms Isoelectronic species, isoelectronic analogy, iso-valence electronic

Frequently Asked Questions

Describes atoms, ions, or molecules that have the same number of electrons and the same electronic configuration. For example, N³⁻, O²⁻, F⁻, Ne, Na⁺, Mg²⁺, and Al³⁺ are all isoelectronic with 10 electrons. Isoelectronic species often have similar properties.

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