Our engaging September AP Teach meeting, “What’s the Attraction with Coulomb’s Law?”, focused on the many ways Coulomb’s Law appears throughout the AP Chemistry curriculum and strategies for helping students craft stronger explanations using it.

Shifra Yonis opened the meeting by discussing how Coulomb’s Law is used in Unit 1 to explain periodic trends. Participants reviewed Question 3 from the 2018 AP Chemistry free-response exam and examined common student misconceptions. Jennifer Cambre then explored how students apply Coulomb’s Law in Unit 2 to describe interactions between cations and anions in ionic compounds, using Question 6 from the 2017 free-response exam to highlight frequent errors in student reasoning. Kristen Vanderveen expanded the discussion to interparticle forces, including ion-dipole interactions, by analyzing sample student responses from Question 1 of the 2025 free-response exam.

Kristen concluded the meeting by sharing a framework that students can use to construct stronger arguments based on Coulomb’s Law. First, students must correctly identify the interacting particles, avoiding common mistakes such as describing nucleus-electron interactions when discussing ions and dipoles. Next, students should compare the magnitude of the charges involved. If the charges are equal, they should then compare interparticle distances. Using this information, students can apply Coulomb’s Law to justify their claims: larger charges lead to stronger attractive forces, while shorter distances between particles also increase the strength of attraction.

In breakout rooms, teachers discussed how they differentiate among applications of Coulomb’s Law and shared classroom strategies that help students write clearer, more accurate scientific arguments.

What’s the Attraction with Coulomb’s Law?

Video highlights from the September 2025 APTeach Session.

View the PRESENTATION SLIDEDECK and access resource links shared in the full presentation.

Watch the APTeach Session Notes and Updates article for summaries of past meetings and announcements for upcoming presentations.

Each one-hour APTeach Zoom session provides 15-20 minutes of discussion centered around a challenging chemistry topic, followed by breakout rooms that allow small groups of teachers to share their best teaching practices related to that content. 

If you aren't already receiving ChemEd X newsletters, create a free ChemEd X account today to stay informed about upcoming events and stay up to date on the wealth of resources available on ChemEd X.