VSEPR calculation for boron trifluoride, BF₃

Boron trifluoride only has six valence electrons and is one of the relatively rare second period covalent molecules that disobeys the octet rule. There are three bonded groups and so no lone pairs. Six electrons implies three electron pairs and therefore a trigonal geometry.

Boron trifluoride, BF₃

Lewis structure:
Central atom:	boron
Valence electrons on central atom:	3
3 F each contribute 1 electron:	3
Total:	6
Divide by 2 to give electron pairs	3
3 electron pairs:	trigonal geometry for the three shape-determining electron pairs

The geometry of boron trifluoride, BF3. You can use your mouse to manipulate the molecule in the right hand "Jmol" image.