Chemistry Teachers' Perception of Students' Difficulties in Reading and Drawing Chemical Structures.

The acquisition of fundamental knowledge in chemical formula language and the ability to graphically represent chemical structures are critical components of chemistry education. Various structural representational forms, such as molecular formulas, Lewis formulas, and skeletal formulas, serve different purposes in describing chemical compounds and require specialized skills to interpret and create. While experts in the field can seamlessly transition between these representational forms, students often face challenges in building the necessary mental models and understanding the design conventions. This study investigates how chemistry teachers perceive and address students' difficulties in reading and drawing chemical structural formulas. Through a survey of 116 chemistry teachers from Switzerland, Germany, Austria, and Denmark, the study explores the introduction of structural representational forms in classrooms, common student errors, and strategies employed to mitigate these errors. Teachers frequently use simpler chemical compounds, such as alkanes and alcohols, to introduce various representational forms and to diagnose typical errors. The most common errors identified include missing or excess atoms, incorrect spatial orientation, and violation of the octet rule. Findings emphasize the importance of gradually introducing complexity in chemical notations, starting with basic structures and progressively advancing to more complex spatial representational forms. Teachers highlight the value of repetition, targeted exercises, and interactive tools, such as augmented reality, to enhance students' spatial reasoning and conceptual understanding. These insights underscore the need for innovative educational resources to support individualized learning paths and improve proficiency in chemical representation.