Intermolecular Forces and Allotropy (HSC SSCE Chemistry): Flashcards

Valence shell electron-pair repulsion theory

Electron pairs maximize distance to minimize repulsion

Linear, $180°$

Trigonal planar, $120°$ angles

Tetrahedral, $109.5°$ angles

Pyramidal (e.g., $\text{NH}_3$)

Bent (e.g., $\text{H}_2\text{O}$)

$109.5°$

Shape = atom positions only; arrangement = all pairs

All pairs: both bonding and lone pairs