Designing, implementing and evaluating a teaching sequence about physical and chemical change for Saudi school students aged 15-16

Differentiation between physical and chemical change in chemistry teaching is both fundamental and problematic. Teaching approaches often rely on using macroscopic descriptions of change processes, which by their nature cannot differentiate between physical and chemical change. The aim of this study was to develop. implement, and evaluate a teaching sequence concerning students' understanding of physical and chemical change processes, based upon a submicroscopic model of the structure of matter. The teaching sequence was implemented with secondary students aged 15•16 in the target Saudi school. A case study approach was employed (one school). Three year 10 classes from the selected school (90 male students) and two chemistry teachers were recruited. For the purpose of designing the teaching sequence, the Leeds Group model was used. In the implementation and evaluation phases the focus was on measuring what teachers and students were expected to do and what they actually did, as well as evaluating what students were expected to learn compared to what they actually learnt. Furthermore, an interview approach was used to explore teachers' and students' views about the designed teaching sequence. A conceptual analysis was conducted which identified six broad areas (families) of key scientific ideas (FKSO. The results of this study indicated that the implementation of the designed teaching sequence, to a large extent, covered the required conceptual content. The results also showed that the students talked to the teacher (and each other), as well as the teacher talking to students. So, the students could control the meaning-making process by their interventions, rather than placing sole responsibility for this on the teacher. The designed teaching sequence was, to some extent, effective in relation to students' learning of physical and chemical change across all six FKSls. However, what students found most difficult in the understanding of the physical and chemical change, through the particle model (submicroscopic level), was how macroscopic descriptions and the submicroscopic level relate to each other and differ from one another. The results demonstrated increases in the level of conceptual understanding achieved by students following the designed teaching sequence, compared to students following the normal teaching approach.EThOS - Electronic Theses Online ServiceGBUnited Kingdo