A Teaching Empirical Study On Promoting Model Cognition Of Chemical Bonds In Senior Middle School Students

"Model cognition" is an important part of chemical core literacy,improving the students' "model cognition" ability is also an urgent requirement for core literacy.High school students' "model cognition" ability refers to the ability to use models to describe chemical research objects,interpret chemical phenomena and regulars,predict possible outcomes,and construct models to demonstrate their understanding and interpretation of chemical facts.The knowledge of chemical bond theory is the core knowledge of the entire middle school teaching,which can explain the essence of the atom forming the material world,the nature of chemical reaction and energy change,etc.But the knowledge of chemical bonds has abstract,microscopic,and incomprehensible characteristics,and is also a difficult point in teaching and learning.The concepts and impressions provided by the model approach can help students better acquire knowledge and improve the cognitive structure of students.this paper selects the knowledge of chemical bonds as the basis for model-based modeling teaching,trying to find new ideas for teaching design to promote students' chemical bond model cognition;Exploring the impact of model cognition on students' learning of chemical bond concepts through practice exploration,thus providing a reference for high school chemistry teaching.Based on a review of existing research on chemical bonds and model cognition at home and abroad,Using chemical bond knowledge as the starting point,the teaching design of model-based modeling is carried out;And carry out empirical research,including the use of teaching design for experimental teaching,through the questionnaire to test the difference between the experimental class and the control class students,and using SPSS 22.0 for statistical analysis,through qualitative interviews,in-depth exploration of students in the chemical bond conceptual model cognitive processdifferences.corresponding conclusions are drawn:(1)Model-based modeling teaching has a positive effect on promoting students' chemical bond model cognition(Knowledge cognition: the average grade of the experimental class is higher than that of the control class,and the “knowledge of the chemical bond conceptual model” constructed by the experimental class students is more comprehensive;Cognition of thinking: Students in the experimental class will use the "Macroscopic model-microscopic essence" thinking to solve the chemical problem,and the control class prefers to use the book and the teacher's "word association" to explain the problem;model teaching expands students' representation of problems.).(2)Model teaching strategies are feasible in the cognitive teaching of chemical bond models.(3)There are some myths about the chemical bond model.(4)Seven teaching cases developed by "model-based modeling teaching".Based on the research results,four corresponding teaching Suggestions were put forward to promote the cognition of the chemical bond model in senior high school students;Finally,it is to reflect on the shortcomings of this study and with a view to improving.