Understanding the triple nature of the chemical bond on submicroscopic level

摘要

The master’s thesis addresses three definitions of chemical bond with particular emphasis on the sub-microscopic level in a comprehensive manner. Slovenian pupils are taught about chemical bond for the first time in the eighth grade of primary school as part of learning about the connection between particles. Due to the abstract nature of the notion chemical bond, it is essential that pupils are encouraged to learn about the topic on the macroscopic, sub microscopic and symbolic level as this is crucial for them to develop an appropriate mental model regarding the chemical bond. The teacher’s explanations, additional explanation in the coursebook as well as consolidation and examination of acquired knowledge using the exercises provided in the workbook or by the teacher help pupils to form the mental model. Despite an integrated approach to learning about the abstract nature of chemical bond, there are still various misconceptions about the particles and chemical bond among pupils. To this end, the empirical part consists of a descriptive analysis of coursebooks and textbooks available in Slovenia on the inclusion of the sub-microscopic level in the explanation and consolidation of the notion chemical bond. We created a three-part test to examine the understanding of the notions regarding chemical bond on the sub-micro level and potential misconceptions of ninth grade pupils (on average aged 14). The findings of the teaching material analysis show that the symbolic level is the most common level in coursebooks and textbooks in particular, followed by the sub-microscopic and macroscopic level and the combination of the sub microscopic and symbolic level. However, the data obtained from the test show that pupils have a better understanding of the chemical bond on the symbolic level than on the sub-microscopic level. They are also more confident and successful in completing the tasks regarding the covalent bond than the ionic bond. Lack of knowledge and, consequently, a low level of success have been shown in tasks which include less well-known pictures of sub microscopic models and, according to Bloom, therefore belong to a higher level of cognitive knowledge. The data also indicate that pupils have difficulty in transforming the models between the presentations, which causes unsuitable mental models. These findings are essential for primary school chemistry teachers as they are revealing the areas that cause the most problems to the pupils. The duty of the teacher is to adapt their classes to the pupils’ needs in order to attain the highest level of comprehension.