A Study On The Cultivation Strategy Of Junior High School Students' Chemical Expression Ability Based On Macro Micro Combination

Chemistry is a basic natural science to study the composition,structure,properties and change law of the matter at the atomic and molecular level.Chemical formula belongs to the symbolic representation in the triple representation of macroscopic,microscopic and symbolic components.Symbolic representation is the bridge connecting macroscopic and microscopic representation.In junior middle school chemistry courses,chemical formula not only plays a connecting role in the study of chemical terms,but also plays an important role in training students' competence to solve some chemical problems.Therefore,this article focuses on the expression of Chemical Formula Training Strategy of the junior high school students.In this paper,we use the two-stage tool of Chelgast to probe into the problems in chemical expressions in junior middle school students,and explore the teaching strategy of developing the ability of chemical expressions in junior middle school students by means of macro-micro combination,the feasibility and effectiveness of these teaching strategies are tested with the case of chemical teaching design and the effect of implementation.According to the principle of combining macro with micro way,this paper puts forward several teaching strategies to cultivate junior middle school students' ability of expression of chemical formula.To understand the meaning of valence from the microscopic structure,to grasp the macroscopic and microscopic meaning of chemical formula by numbers,and to get through the difficulty of reading and writing chemical formula through writing pithy formula.