VSEPR theory facts for kids

The shape of a molecule or ion is determined by the repulsion between the electron pairs surrounding the central atom.

Valence Shell Electron-Pair Repulsion Theory

- Only the electron pairs arranged round the central atom in a covalent molecule need to be considered

- Pairs of electrons repel each other and move as far apart as possible

- Lone pair-lone pair repulsion is greater than lone pair-bonding pair repulsion which is greater than bonding pair- bonding pair repulsion

- The actual shape of species is determined by the atoms attached round the central atom (and influenced by the lone pairs of electrons)

- All bonds - single bonds, double bonds and triple bonds - take up the same space.

Images for kids

Example of bent electron arrangement. Shows location of unpaired electrons, bonded atoms, and bond angles. (Water molecule) The bond angle for water is 104.5°.
Xenon hexafluoride, which has a distorted octahedral geometry.
Hexamethyltungsten, a transition metal complex whose geometry is different from main group coordination.
Sulfur tetrafluoride has a steric number of 5.