Molecule geometry

The title of the Project: Molecule geometry

This virtual laboratory is intended for use in chemistry classes on the following topics:

  • 8th grade. Chapter IX. “Types of chemical bonding”.

Objectives:

  • to explore bonding and molecular shapes
  • to analyze real-world molecules

Practical part

This simulation by PhET allows students to explore how atoms bond and the resulting molecular shapes.

  1. Launch the simulation. There are two screens to use: “Model” and “Real molecules”. Click on the “Model” screen.

The Model Screen

This screen allows you to build your own molecules!

2. In the center, you’ll see a basic 3D model of a molecule with one central atom and two single-bonded atoms. Click and drag to rotate it.

3. Click on the bonding icons to connect single-, double- or triple-bonded atoms to a model. Observe how the molecule’s shape changes as you add atoms.

4. Use the red button to remove atoms one by one or the yellow button to remove them all at once.

5. Checking the “Molecule geometry” box in the “Name” section  displays the predicted molecular shape (e.g., tetrahedral, linear).

6. Checking the “Show Bond Angles” box in the “Options” section displays the angles between bonds. See how these angles change as you add atoms.

7. The “Reset” button clears the building area so you can start over.

8. Take some time to explore the screen and build various molecule shapes. How many different molecular geometries can you create? Do all of them exist in real life?

The Real Molecules Screen

Now, let’s switch to the “Real molecules” screen through the navigation bar below. This screen showcases pre-built molecules for you to observe.

9. Click the dropdown menu to choose a molecule from the list to investigate.

10. The central panel displays the chosen molecule’s 3D structure

11. The “Name” and “Options” sections provide the same information as in the Model Screen.

12. Analyze the provided molecules and explain how the number of chemical bonds influences the angles between those bonds.

Conclusion

This simulation provides a student-centered environment for exploring the fundamental concepts of bonding and molecular shapes. Through building virtual molecules and observing pre-built examples, students gain valuable experience in visualizing and predicting the three-dimensional structures of molecules. This interactive tool serves as a bridge between theoretical concepts and practical understanding, fostering a deeper appreciation for the world of molecular chemistry.