A Study Of Question-driven Case Teaching Based On The Concept Of Change And Balance ——Taking Halogen As An Example

"The idea of change and balance" is the core idea of chemistry,and is one of the five components of high school chemistry core accomplishment.The knowledge of elements and compounds in the compulsory chemistry course of high school is an important carrier of the attainment of "change concept and balance thought".The section of chemical balance in the selective compulsory course module "Principle of Chemical Reaction" is the beginning for students to establish the idea of balance movement and analyze the reaction limit qualitatively and quantitatively.How to break the barriers of textbooks,establish the relationship between chemical equilibrium and elements and compounds,deepen the understanding of chemical equilibrium,deepen the understanding of elements and compound properties,and improve the literacy level of "change concept and balance thought",is the research direction of this paper.Firstly,through literature review,the author defines the related concepts of "change concept and balance thought" and seeks for the fusion point of element and compound knowledge and chemical balance content.Then in the work unit,two parallel classes in grade two of senior high school were selected for questionnaire survey and comparative experiment.Combined with the investigation,this paper puts forward teaching strategies to cultivate students’ core literacy of "change concept and balance thought",including :（1）mining situational materials to guide students to improve their literacy in situational problem-solving activities.（2）The design has hierarchical and systematic driving questions,prompting students to think deeply.（3）Pay attention to inquiry experiment,train students to construct the understanding of material change from the perspective of balance.（4）Establish cooperative groups and establish good communication and learning relationships.According to the connotation,course objectives,performance level and academic quality level requirements of "Change concept and balance Thought" in Chemistry Curriculum Standards for General Senior High Schools（2017）,and the required courses "Theme 2: " Common inorganic substances and their Applications " content requirements,teaching tips and academic requirements,finally selected from the perspective of chemical equilibrium,the halogen elements and compounds of the properties of in-depth research.Based on the proposed teaching strategy,a question-driven teaching design is carried out to carry out heterogeneous teaching practice for the experimental class and the control class.Through three times before,during and after test test,the effect of the implementation of teaching design,proves the element and compound knowledge associated with chemical equilibrium principle,and then collaborative in problem teaching,to promote students’ ideas of changes and balance " literacy level on the one hand,this is a very valuable perspective.In this perspective,the teaching strategy proposed by the author has played a practical role in practice.It is hoped that this study can provide some reference for cultivating students’ accomplishment of "change concept and balance thought".