Science Practice: Developing and Using Models

Equilibrium Snowball Fight

For dynamic equilibrium, I like to use a physical analogy that pits students against each other in a classroom-wide “snowball” fight. Not only is this activity great for building students’ conceptualization of dynamic equilibrium, it is also really fun!

Measuring Surface Tension to Investigate Intermolecular Forces

Like most concepts in chemistry, intermolecular forces takes a bit of imagination and critical thinking to fully comprehend and apply when explaining a variety of situations. Though demonstrating the presence of these forces in a simple and explicit manner can easily be done, I wanted to change how I introduced IMFs a bit this year by focusing on a more data-to-concepts approach.

Lewis Dot, VSEPR Shape, Polarity and Intermolecular Forces Activity Sheet

Determination of Lewis Dot structures and visualization of the shapes of molecules using VSEPR theory is an example of an abstract concept that students often find difficult to learn. I have found it useful to have a single worksheet/packet that my students can add to as we cover Lewis dot structures, resonance, VSEPR shapes, polarity, and intermolecular forces.

Elements, Compounds, and a Vocabulary Card Sort

How many of you could recite, word for word, a definition you learned in school? When you first memorized the definition, you could state “inertia is a property of matter”, or “density is mass over volume.” However, you struggled to apply it to a new situation and maybe you were unsure of how to construct a model of what it meant.

Analogy Experiment—Projectile Pennies with Rutherford

Atomic theory is a common topic throughout any introductory chemistry course. It is likely that Rutherford’s gold foil experiment gets at least some attention in your course. I have used a simple activity that gives students an opportunity to replicate Rutherford’s experiment through an analogy experiment that may allow for easier conceptualization of the experiment itself and provide additional support for model development.

Conversations, Confessions, Confusions (and hopefully some Clarity) on Electronic Configurations

A complete understanding of why each element has a particular electronic configurations is a very complex subject. Even so, some confusion regarding the electronic configurations of the elements may be alleviated by looking at the physical properties of the electronic orbitals.

Geometric Approach to Lewis Structures

If you look at any chemistry textbook, you will see Lewis structures introduced long before electronic and molecular geometries. This makes sense since you need Lewis structures to determine molecular geometry. Unfortunately, research has shown that students often do not recognize that the purpose of drawing Lewis structures is not to create the structure itself but to use it as tool to understand the properties of the molecule (Cooper, Grove, Underwood & Klymkowsky, 2010).