Harness the power of PowerPoint when teaching molecular motion to help students better understand the sub-microscopic world

A colourful illustration showing water molecules on a computer screen

Source: Adapted from © Gorbash Varvara/Shutterstock

Asking students to generate animations of molecular dynamics could give you a better insight into their thinking

Researcher Guspatni Guspatni recently investigated student teachers’ conceptions of molecular motion by analysing PowerPoint animations they had made. Guspatni suggests this approach could be translated into the classroom to assess students’ understanding of molecular dynamics.

Kinetics and molecular dynamics are hard to represent with static visuals. Advances in computer-based animation have made it possible to depict dynamic processes, helping students to see the unseeable. Allowing students to generate their own animations engages them in meaningful learning and fosters more accurate mental models. PowerPoint is an ideal tool for students: it is ubiquitous and makes it relatively easy to apply animation effects to graphical entities.

Molecular misconceptions

25 student teachers participated in the study. They had already completed tutorials on motion effects in PowerPoint and on multiple representations in chemistry. They then created animations depicting the motion of water molecules and wrote an explanation for three types of motion a particle can have. During the assessment, Guspatni classified animations as correct or incorrect, and explanations as correct conceptions or misconceptions.

All the participants appeared to hold correct conceptions of translation, showing molecules moving from one point to another, although some did not animate a change of direction following a collision. Many seemed to hold correct conceptions of rotation, illustrating the rotation of a molecule around its own axis. However, a few incorrectly illustrated rotation as the motion of a molecule in a circular path. Virtually all the student teachers demonstrated misconceptions around molecular vibration. They treated it as a whole particle shaking rather than as bond lengths or angles oscillating.

Conceptions expressed in animations were not substantially different from those in written explanations, with a few mismatches evident around molecular rotations.

It is notable that only a few participants modelled the three types of motion concurrently by showing a molecule rotating and vibrating as it moves. Most illustrated each molecule only undergoing one type of motion – some molecules moving, some rotating and some vibrating.

In the classroom

While the same activity may not translate directly into a school classroom, it would be accessible to post-16 students with some guidance. However, this approach can be applied at any level of chemistry by adjusting the model to match the needs of the students. For example, 11-year-olds in the UK and Ireland are taught about the motion of particles in different states of matter. The activity brings computers into chemistry in a way that helps students understand and manipulate the sub-microscopic world.

Teaching tips

  • Use the activity in the study with your own students to identify and address any misconceptions they have around molecular motion. Guspatni noted that ball-and-stick models would have more explanatory power than space-filling models, particularly for molecular vibrations. 
  • Use this as an opportunity to carry out formative assessment. This could involve students contributing to assessment criteria that they could apply to their own self- and peer-assessment.
  • A written explanation is a valuable way of triangulating the exercise by providing additional opportunities to identify and address misconceptions. Guspatni suggests asking higher order thinking questions for a more complete picture of what a student is thinking. This could include asking them to justify the design they implemented. Self-assessment could require students to reflect on their experiences.
  • Many secondary students already have PowerPoint skills that exceed teachers’, but it might be helpful to do a skills audit prior to the task. Ask students to share tips and techniques with others when they have finished. The article also includes helpful appendices with instructions on how to create more sophisticated types of PowerPoint animation that you can refer to.