Comparison Of High School Chemistry Textbooks And Teaching Case Development Based On Valence-Species Diagram

With the promulgation of "National Chemistry Curriculum Standards for general High School(2017)",2019 [Luke Edition] textbooks are also published,The textbook has increased the importance of valence-species diagram.Based on literature research and basic theoretical research,a systematic comparative study on the "Nitrogen Cycle" in 2019 [Luke Edition] textbook(hereinafter referred to as: new [Luke Edition])and 2007 [Luke Edition] textbook(hereinafter referred to as: old [Luke Edition])is conducted,and focusing on the relevant content of valence-species diagram is compared;Based on the relevant requirements of the 2017 version of the curriculum standards,the relevant theoretical basis research and the guidance of a comparative study of new and old textbooks,the article developed an innovative teaching case of "nitrogen and its compounds" stage review lesson with the construction and application of valence-species diagram as the core,and carried out research on teaching practice.The study promotes the introduction of valence-species diagram into teaching,and improves the learning effect of element compound content.It provides the necessary teaching model reference for the review lesson of element compound based on valence-species diagram.The study is divided into six parts,as follows:The first part is introduction.It mainly elaborates the background,the literature review at home and abroad,the determination of research questions,the research methods,the research significance and innovation points.The second part is core concepts and theoretical basis.It mainly defines the concepts of "valence-species diagram","chemical concept" and "review lesson".And the connotation of "Bruner's Theory of Cognitive Structure Learning" and "Recent Development Zone Theory" and its guiding role in this teaching case are expounded.The third part is comparison of old and new textbooks.From the perspective of content selection,architecture,and presentation,a systematic comparison on the "Nitrogen Cycle" section in the old and new [Luke Edition] textbook is made,and focusing on the relevant content of valence-species diagram is compared,conclusions and related teaching recommendations are drawn.Through comparative research,the following conclusions are reached:(1)In terms of content selection,the core content of the two textbooks remains the same,and both focus on the selection of content that is closely related to production and life.However,the new textbook has greater coverage of relevant content,increasing the physical properties of nitrogen and other contents.In addition,the expressions of "fading" and "most" are more scientific and accurate than the old textbook,and the new textbook pays more attention to the infiltration of chemical concepts such as element,classification,and transformation.(2)Architecturally,the macro position of "Nitrogen Cycle" section in the two textbooks is almost unchanged,and the overall orchestration ideas are consistent.However,the content of the second section of the new textbook "Nitrogen Cycle" is more transitional.For nitrogen,nitric oxide and other related knowledge,sequential presentation from apparent phenomena to scientific principles is adopted,and it is more in line with the law of students' cognitive development.(3)In terms of presentation,both textbooks have various columns and exquisite illustrations,and the experimental columns and experimental installation illustrations are most.However,in terms of experimental teaching,the new textbook pays more attention to open experimental inquiry;in terms of problem sets,the new textbook pays more attention to the level and openness of the exercises;in terms of environmental protection thought penetration,the new textbook pays more attention to the transmission of environmental protection ideas from the front.(4)For valence-species diagram,from the perspective of teaching methods,both textbooks focus more on guiding students to find the connection between knowledge independently,and using valence-species diagram to organize element and their compounds knowledge.In terms of the importance attached to valence-species diagram,the new textbook is attached more importance to,and the content of valence-species diagram is obviously more than that of the old textbook,and the new textbook is presented in the form of combining words and pictures,and effectively avoids singleness.The fourth part is the development of teaching case.Guided by the related requirements of the 2017 version of the curriculum standard,related theoretical foundations,and a comparative study of the old and new [Luke Edition] textbooks on the "Nitrogen Cycle" section,the article developed an innovative teaching case of a review course of "nitrogen and its compounds" based on valence-species diagram.The fifth part is the study of teaching practice.Through the implementation of the lesson "nitrogen and its compounds" in two classes with similar academic performance and post-test questions and questionnaires,the following conclusions are obtained: the application of valence-species diagram enables most students in both classes to be better master the systematic knowledge of "nitrogen and its compounds";the experimental class that accepts the teaching case of Chapter 4 has better achievement results of the curriculum than the control class.After teaching practice,put forward strategies to improve this case teaching:(1)In the process of teaching,increase the chemical history of industrial nitric acid and other related nitrogen-containing substances,guide students to experience the difficult process of scientist research,and penetrate core literacy for scientific attitude.(2)Set challenging learning tasks in the student's nearest development zone,guide students to solve problems gradually through inquiry,and break through the teaching difficulties.(3)Establish a knowledge system,implement teaching goals,and form chemistry concepts.The sixth part is the staged results and future research prospects.It summarized the research results at this stage and reflected the shortcomings of the research,and proposed the future research directions and goals.