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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

AXE notation

A label for a VSEPR class: A is the central atom, X each bonded atom and E each lone pair on A, written AXmEn\mathrm{AX}_m\mathrm{E}_n. Each class has one electron-domain geometry and one molecular geometry.

Central Cl atom bonded to 3 F atoms, with 2 lone pairs.FClFF90°180°Ideal bond angles: 90°, 180°
ClFX3\ce{ClF3} is AX3E2\mathrm{AX_3E_2}: T-shaped.

Example

HX2O\ce{H2O} is AX2E2\mathrm{AX_2E_2} (bent), PClX5\ce{PCl5} is AX5\mathrm{AX_5} (trigonal bipyramidal) and IX3X−\ce{I3-} is AX2E3\mathrm{AX_2E_3} (linear).

See alsoSteric numberVSEPR theoryMolecular geometry