Electron-domain geometry and molecular shape
VSEPR distinguishes the arrangement of electron regions from the positions of atoms.
Key knowledge
In the VSEPR model, bonding regions and lone pairs around a center favor spatial separation. A single, double or triple bond counts as one electron region. Two through six regions give ideal linear, trigonal-planar, tetrahedral, trigonal-bipyramidal and octahedral electron-domain arrangements. Molecular shape describes atom positions, omitting lone-pair positions: four regions with one lone pair give a trigonal-pyramidal arrangement, and with two lone pairs a bent arrangement.
Conditions and scope
- A qualitative model for suitable localized main-group molecular structures; it is not a universal transition-metal model.
- Ideal domain arrangements do not guarantee exact experimental angles. Lone pairs and differing bond environments can distort them.
Sources · 2
References
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Evidence and review
Electron-domain counting and the distinction between domain arrangement and atom geometry.
2026-10-10 · Independent Mathematics and Information editor (AI editorial/source review; not the Chemistry/Biology/Earth author). The specified introductory inventory has no unresolved demonstrated material gap after the changes and body-based reuse. Existing advanced references retain their historical scoped approvals. English-only reference prose and explicit Lithuanian-translation-pending status are preserved.
Foundational review
2026-10-10 · Independent AI editorial inspection of this new compact reference entry, its equations, applicability, sources and knowledge connections.
Sources from other places
Scope or convention differs
Electron-domain and lone-pair geometry in simple main-group molecules.
A multiple bond counts as one domain; predicted angles are approximate.
Siyavula
- Physical Sciences 11: Molecular shape South AfricaEnglish
§3.2 VSEPR: bonding and lone-pair groups; shape table
- Physical Sciences 11: Molecular shape
Entry details
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