Commonly Tested Lewis Structures
We draw Lewis Structures to predict:
-the shape of a molecule.
-the reactivity of a molecule and how it might interact with other molecules.
-the physical properties of a molecule such as boiling point, surface tension, etc.
Drawing the Lewis Structure for BF3
Video: Drawing the Lewis Structure for BF3
For the BF3 Lewis structure, calculate the total number of valence electrons for the BF3 molecule. There are a total of 24 valence electrons for the BF3 Lewis structure. After determining how many valence electrons there are in BF3, place them around the central atom to complete the octets.
Boron is the least electronegative atom in the BF3 Lewis structure and therefore goes at the center of the structure.
Boron is an exception and only needs 6 valence electrons in its outer shell. If we check the formal charges for the BF3 Lewis structure we will find that they are zero even though B only had six valence electrons. This tells us that we have the best Lewis structure for BF3.
Video: Drawing the Lewis Structure for BF3
It is helpful if you:
- Try to draw the BF3 Lewis structure before watching the video.
- Watch the video and see if you missed any steps or information.
- Try structures similar to BF3 for more practice.
List of Lewis Structures
| Acetone | BF3 | BH4- | BrF5 | BrO3- | C2H2 | C2H4 | ClO- |
| CH4 | ClO2- | ClO2 | ClO4- | CO | CS2 | H2O | H3O+ |
| HCl | HNO3 | I3- | ICl4- | IF5 | N2 | N3- | NH2OH |
| NH3 | NO2- | NO2 | NO3- | O2 | OF2 | PCl5 | PH3 |
| PO33- | PO43- | SCl2 | SF4 | SF6 | SO3 | SO42- | XeF2 |
| XeF4 |