Experimental Study On Development Of The Middle School Students' Understanding Core Chemical Concepts

Training students'scientific literacy is an eternal goal of science education.Deeply understanding chemistry science and developing basic chemical conceptions is an important aspect of improving students'scientific literacy .Deeply understanding core chemical concepts is the demand of understanding chemistry science,forming basic chemical conceptions and developing thinking ability. Core chemical concepts have the characteristics of abstraction and generalization and strict logic,so they are not only the vital and core contents but also the difficult points in chemistry teaching.Therefore,exploring the existing problems in students'understanding of the core chemical concepts and contrapositively developing students'understanding of core chemical concepts has important theoretical value and practical significance.Based on the study purpose above,there are three main tasks in this paper: (1) Investigate the current situation of the students'understanding of core chemical concepts in different grades of the middle school in order to reveal the existing problems in students'understanding of the core chemical concepts. (2) construct concept-based course aimed at promoting students'understanding of the core chemical concepts. (3) Study experimentally the effectiveness of the concept-based course. Through questionnaire survey in the middle school students, some problems are found in students'understanding of the core chemical concepts.Most of them are in lower level in understanding the core chemical concepts of molecule ,atom,atomic structure, chemical formula and valence and chemical bond. They only pay attention to what the concept is and how to use the concept but not how to develop the concept and whether it is reasonable .They are lack of epistemology thinking to the chemical theory and ability to integrate effectively the correlating and strcture-unified concepts system.Moreover, students'understanding of the core chemical concepts isn't developed as their chemical knowledge increases.Aimed at the problems above,this study conducts the curriculum practice,which integrates the core chemical concepts revolving the chemical regressing problem and reflects the core chemical concepts from the point of epistemology .Main conclusions of this dissertation are that the course, composed of discussing the core chemical concepts revolving the chemical regressing problem, studying the chemistry microcosmic cognition from the point of the NOS, reflecting the core chemical concepts using the WWHW epistemology model,thinking electronic motion from the point of the view of energy, can develop effectively students'understanding of the core chemical concepts.