Senior pre-service chemistry teachers’ perceptions, alternative conceptions and knowledge structure regarding radiation and radioactivity

This study investigates the perceptions, alternative conceptions, and knowledge structures of senior pre-service chemistry teachers regarding radiation and radioactivity prior to their enrollment in a nuclear chemistry course. A phenomenographic design was employed to reveal the qualitatively different ways in which these concepts are perceived and conceptualized. The phenomenographic analysis was conducted in three stages to identify the key issues within participants’ perceptions and to organize the qualitative variation in these perceptions into hierarchically related categories. These categories were then secondarily interpreted to identify alternative conceptions and to map the underlying knowledge structures that illustrate how fundamental nuclear chemistry concepts are structurally interconnected within participants’ mental frameworks. At the end of the study, SPSCTs’ perceptions of radiation were grouped into five main issues: (1) ray, (2) emission of ray, (3) wave, (4) energy, and (5) emission of energy; while their perceptions of radioactivity were grouped into six main issues: (1) emission of radiation, (2) decomposition, (3) radiation, (4) energy, (5) reaction, and (6) matter. Energy emerged as the only common issue across both outcome spaces, indicating that senior pre-service chemistry teachers fundamentally associate both phenomena with energy. At the same time, radioactivity was primarily conceptualized as a process grounded in nuclear instability and material transformation, yet only partially distinguished from the physical phenomena of radiation. The findings further indicate persistent alternative conceptions among senior pre-service chemistry teachers, including the interchangeable use of radiation and radioactivity, the belief that all forms of radiation are harmful, and the alternative conception that nuclear reactions are a type of chemical reaction. These results underscore the need for targeted instructional strategies in teacher education programs to address structurally embedded conceptual confusions before formal nuclear chemistry instruction begins.