Skip to content
CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Bond angle

The angle between two bonds that share a central atom, e.g. H–O–H. VSEPR gives ideal values (180°, 120°, 109.5°, 90°); lone pairs and multiple bonds squeeze nearby angles below them.

Central N atom bonded to 3 H atoms, with 1 lone pair.HHNH109.5°Ideal bond angle: 109.5°
The lone pair on N closes the H–N–H angle to about 107°.

Example

CHX4\ce{CH4} 109.5°, NHX3\ce{NH3} ≈ 107°, HX2O\ce{H2O} ≈ 104.5°: each extra lone pair narrows the angle.