Research On Chemical Bonding Teaching That Promotes Conceptual Change

Chemical bonding is an important concept in middle school chemistry and plays an important role in the structure and system of chemistry.Bonding is not a separate entity,it describes the "bonding" of atoms due to electrostatic interactions and quantum mechanics.Therefore,this concept has a strong abstraction and theory,many students in the learning process can not correctly understand the concept of chemical bonding,resulting in a large number of alternative conceptions,which brings great challenges to chemical bonding teaching.At the same time,there are two problems in the teaching of the concept of chemical bonding in high schools in China.One is that the "octet rule" is overemphasized,and students do not realize the nature of chemical bonding.Second,in traditional teaching,the dichotomy of elements leads to the dichotomy of chemical bonding.All these seriously affect students' scientific understanding of the concept of chemical bonding.In order to help students learn the nature of chemical bonding more scientifically and effectively,many experts and scholars at home and abroad have conducted extensive exploration and in-depth research on the alternative conceptions and concepts related to chemical bonding teaching.Based on this,this research is based on reviewing the domestic and foreign chemical bond alternative conceptions and concepion teaching research to comb and summarize,fully absorb and draw on the research results at home and abroad,and creatively develop a four-tier diagnostic test as a testing tool,And selected students in the second and third grades of high school as the test objects for actual testing.The study found that there are certain differences in the alternative conceptions of chemical bonding among students of different grades.The number of alternative conceptions held by senior third-year students(6)is about one-half of that of senior second-year students(11).As time goes by and grades rise,most of the weakly alternative conceptions will gradually disappear,and the transformation will be successfully achieved.However,some moderate and strong alternative conceptions are still difficult to change.The research further analyzed the reasons for the generation of alternative conceptions in combination with the literature research method and the interview method,and based on this,proposed effective teaching strategies to promote the conceptual transformation of chemical bonding,mainly including setting up cognitive conflicts and stimulating students' deep thinking;Electrostatic force clarifies the concept of chemical bonding;Enriches visual representations to break through the microscopic and abstract problems of chemical bonding;Choose appropriate analogies to visually "show" the formation process of chemical bonding.On the basis of accurately grasping the students' alternative conceptions and fully understanding the learning situation,the author has conducted an in-depth analysis of the textbooks and curriculum standards,applied the teaching strategies of promoting the conceptual change of chemical bonding constructed in this research,and carried out the teaching design to promote the concept transformation.After that,the author randomly selected two classes in the second grade of a certain school as experimental classes,and the other two classes as control classes,and conducted research on teaching practice.After the lecture,the author conducted a unified post-test on the experimental class and the control class,and processed the data through SPSS,Excel and other software,and analyzed the data from the two dimensions of total score,average score,and heterogeneity.The results show that :(1)The total and average scores of the experimental class were significantly higher than those of the control class(Sig.=0.000);(2)The number of alternative conceptions in the experimental class about chemical bonding was significantly less than that of the control class.In the post-test of chemical bonding,there were 3 typical alternative conceptions in the experiment class,while there were still 10 typical alternative conceptions in the control class.This indicates that the teaching strategies for promoting conceptual transformation constructed in this paper is an effective teaching strategy,which plays an important role in eliminating students' alternative conceptions and improving their conceptual understanding.