Study On Surveying Learning Difficulty And Teaching Strategy For High School Students In Chemistry Threefold Representation

Chemistry is a natural science subject that research the materia's constitutes, structures and the changing regulations on atom and molecular levels. As the chemistry continuously develops, it accumulats a wealth of knowledge, rules, and research methods, and gradually forms its own unique thinking mode.As a survey suggests, in those classes whose grades are poor in chemistry. Chemistry learning is essentially about macroscopic, microscopic and symbolic of the construction of three representations and students can flexibly transfer between the three representations. However, many students can't effectively establish macroscopic, microscopic and symbolic representations and the connection between them, which creates learning difficulties.Understanding and establishing the connection of macroscopic, microscopic and symbolic representations, totally different from the study of other science, has been the most characteristic way of thinking in international community. Threefold representation embodies the characteristics of chemistry and introduces students to unique charm of chemistry. A large quantity of studies have proved that threefold representation is an effective way of mastering chemistry and solving problems concerning it.This study is aimed to learn about high school students' triple structure of thinking ability and understand the minds of high school students through interviews. The survey shows the students are equipped with the basic capability of threefold representation in a sense. Macroscopic representation ability is strong while microscopic and symbolic representations are relatively weak and most of the students surveyed find them hard. At the same time, there are some difficulties and obstacles on the transformation of macroscopic, microscopic and symbolic representations.Author of this paper selected two of his classes in grade one of high school at random for research, one as the experimental class and the other the control class.Accordingly, in an effort to develop the thinking ability of threefold representation in the experimental class, we set up four teaching strategies:(1) strengthening the consciousness of conversion between different representations;(2) optimizing the teaching media; (3) highlight the importance of experimental teaching;(4) promoting the construction and development of students'concept of particles. The experimental class performed the teaching strategies strictly. Three months later, a survey designed as test, comparison and analysis was conducted between the two classes and also some of the students in experimental class were interviewed. The outcome shows that threefold representation can be cultivated and strengthened by teaching.The result also proves that threefold representation contributes to chemistry learning well and our strategies are effective.Finally, we summarized and reflected the exisiting problems in the research and pointed out the direction for further study.