Attraction vs. repulsion – learning about forces and energy in chemical bonding with the ELI-Chem simulation
This work seeks to solve one of the basic problems in chemistry learning: understanding the chemical bond as a dynamic equilibrium between attractive and repulsive forces. This force-based model is difficult to grasp, as there are no analogues from everyday life for both attractions and repulsions happening simultaneously. In addition, current teaching approaches often mislead by using mainly the ‘octet rule’ heuristic. As a result, students construct naïve models of the chemical bond, usually viewing atoms as solid balls that are attached to each other in order to “achieve an octet.” To represent the force-based dynamics of the bond, we designed the ELI-Chem learning environment. This environment enables interaction as an atom with another atom while observing the underlying forces and the potential energy curve. Our theoretical framework is based on Embodied Learning theory by relating conceptual learning to bodily experiences. The study uses qualitative and quantitative methods with 21 high school chemistry students in a pretest–intervention–posttest design. During a 40 minute activity with the ELI-Chem simulation, students were prompted to discover the underlying forces of bonding and relate them to energy changes. Findings show that learning with the ELI-Chem simulation supports students in gaining the knowledge elements that are required to build the dynamic force-based mental model of chemical bonding, and to conceptualize chemical energy as due to forces. Finally, the design principles of the ELI-Chem environment are discussed. Aligned with science standards, attending to students’ difficulties, and using the advantages of a computer simulation, the ELI-Chem environment provides an appropriate representation of chemical bonding, which is more valid scientifically yet makes the abstract concept accessible.