Understanding Chemical Bonding: The Development of A Level Students' Understanding of the Concept of Chemical Bonding.

A level chemistry students’ developing understanding of the chemical bonding concept was investigated using a grounded theory approach. Sequences of in-depth interviews with individual students were supplemented by a range of complementary data sources. The thesis presents case studies of two of the students, as well as describing general features that emerged during the research. It was found that several aspects of the orbital concept were not well understood by the students. Students were found to have alternative conceptions of how electrostatic charges interact, and they often failed to appreciate the role of such electrostatic interactions in the formation and breaking of chemical bonds. It was also found that there was widespread use of inappropriate explanatory schemes based upon the notion of a 'full [electron] shell' or 'octet' as the rationale for the occurrence of chemical bonds and chemical reactions. Progression in understanding chemical bonding amongst these A level students largely concerned the transition between this alternative ‘octet thinking and the electrostatic explanatory schemes of curriculum science. This finding is used to provide advice to teachers, text-book authors and science curriculum planners. This thesis contributes to a number of contemporary debates concerning the nature of learners’ alternative ideas in science. It is demonstrated that individual learners do hold coherent and stable explanatory schemes that are inconsistent with curriculum science. Moreover, learners hold multiple frameworks in cognitive structure to explain the same phenomena. It is also shown how, in learning chemistry, alternative conceptions deriving from intuitive theories about the physical world may be less significant than those based on material that is taught incorrectly, or that is presented to learners who do not have the prerequisite knowledge to construct the intended meaning