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Modeling Molecules with VSEPR

This activity is meant to be used after students have done the simulator-based activity, had some notes to introduce the concepts of VSEPR, and drawn some molecules while identifying the 3D shapes. The prior experience will make it easier to build the correct models with the kits for this activity.
In this activity you will review the names of the shapes of molecules from the VSEPR (Valence Shell Electron Pair Repulsion) model and build molecules using a model kit. The idea is to make the shapes more visible to your imagination by making them concrete and hands-on. Work in groups of four students to complete this activity.

On this page you will review the shapes of molecules as predicted by the VSEPR Model. Use the given numbers of bonds and and lone pairs in each row to find the total number of electron domains. Electron domains are either a bond or a lone pair (or non-bonding pair) of electrons. Then name the geometry based on the total number of electron domains. Finally, name the molecular geometry and add a 3-D drawing of the shape. One is done for you to show you how it works.

Number of BondsNumber of Lone PairsTotal Number of Electron DomainsElectron GeometryMolecule GeometryBond AnglesDrawing
1 0 


 		    
2 0 


 		    
3 0 


 		    
2 1 


 		    
4 0 


 		    
3 1  4  tetrahedraltrigonal
pyramidal		109.5°3-D.Molecule.Model.Trigonal.Pyramidal (88K)
2 2 


 		    


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You will be using a molecular model kit, which contains:

What to do:
  1. Build a 3-D model of each molecule below using the kit provided.
    Most models you build will have a bond at every bonding site (or hole) on every atom. Only one does not.
    Double or triple bonds are made using the long bonds, which bend.
  2. After you build the molecule with the kit, draw a Lewis diagram for each one.
  3. After building the model and drawing the Lewis diagram: identify the 3-D shape or shapes using the model and your drawing. Molecules with two or more ‘central’ atoms will have a shape name for each one. The shape names are: linear, trigonal planar, bent (120° angles), tetrahedral, trigonal pyramidal, bent (109.5° angles).
  1. CO2
    Lewis Structure:


    VSEPR Shape:
  2. H2CO
    Lewis Structure:


    VSEPR Shape:
  3. NO2–
    not all holes are filled for this model!
    Lewis Structure:


    VSEPR Shape:
  4. CH4
    Lewis Structure:


    VSEPR Shape:
  5. NH3
    Lewis Structure:


    VSEPR Shape:
  6. H2O
    Lewis Structure:


    VSEPR Shape:
  7. C2H6
    Lewis Structure:


    VSEPR Shapes:
  8. C2H4
    Lewis Structure:


    VSEPR Shapes:
  9. CH4O
    Lewis Structure:


    VSEPR Shapes:
  10. C2H6O
    Lewis Structure:


    VSEPR Shapes:
  11. C2H6O a different structure
    Lewis Structure:


    VSEPR Shapes:
  12. CH3CHO
    Lewis Structure:


    VSEPR Shapes:
  13. C2H4O2 both oxygen atoms attach to the same carbon atom
    Lewis Structure:


    VSEPR Shapes:
  14. C2H5NO the oxygen and nitrogen atoms attach to the same carbon atom
    Lewis Structure:


    VSEPR Shapes:
Last updated: Feb 01, 2023       Home