The More Explicit, the Better? How the Indication of Electron Lone Pairs Affects Students’ Consideration of Resonance in Organic Chemistry

Proficiency in decoding and interpreting representations plays a critical role in learning in Organic Chemistry. However, abundant research within and beyond chemistry education suggests that learners tend to focus their attention on surface features and struggle to discern and use relevant features in solving tasks. With regard to the resonance concept, it has been shown that learners have difficulties in identifying the possibility of electron delocalization in molecular structures, eventually resulting in a limited integration of this concept in problem-solving. While the explicit display of lone pairs has been recommended and is typically used in teaching to indicate the source of electron-pushing arrows, explorative results across different studies yield ambiguous findings about its helpfulness for learners in successfully discerning the possibility of electron delocalization. To substantiate these findings, a quantitative study was conducted with undergraduate students (N = 699) enrolled in an Organic Chemistry I course. Students solved an online survey in which they had to decide on the possibility of resonance stabilization for different molecular structures varying in their structural features. Using paired-sample t-tests, differences in students’ performance on their resonance-related decision-making for items (not) exhibiting electron lone pairs were examined. Results suggest that students’ perception of resonance stabilization significantly depends on the display of lone pairs, highlighting the necessity of teaching resonance-related pattern recognition in a more reflective way.