Study On Teaching Design And Practice Of Chemical Acid-alkali And Salt In Junior Middle School Based On Classification View

The knowledge of chemical acid-base and salt in junior high school is complicated and comprehensive in terms of topics.Therefore,the learning of acid-base and salt is truly the key to and difficulty of successful chemical learning during junior high school.Students might feel that it is easy to learn this part of the knowledge but difficult to memorize,or simply not fully master the way to get them into usage.In recent years,chemistry science education requires that teaching should not only help students to simply memorize or understand,but to change from "knowledge-orientied" to"conceptual construction",helping students form basic concepts of chemistry.As a consequence,in the junior middle school period,it is of significant teaching value that how the teachers help students construct the classification view in learning acid-alkali and salt.This study is trying to solve the following problems:(1)What is the cognition of the classification view of the students before learning acid-alkali and salt?(2)How to reflect the process of constructing students' classification view in the teaching design of acid-alkali and salt?(3)Can the teaching design based on classification view have a positive impact on the construction of students' classification view?The research is divided into five parts.The first part is the origin of the research,a literature review at home and abroad,the purpose and significance of the research,the research content and methods.The second part is the core concept and the theoretical basis,it defines the "chemistry concept","classification view" and "teaching design".The third part is the use of questionnaire to get a clear view of the preliminary cognition of classification view.The fourth part is the analysis of the knowledge of acid-alkali salt in junior high school.It mainly studies the curriculum standards,the status and role of acid-alkali salt knowledge,and the content of acid-alkali salt knowledge.The fifth part is the analysis and implementation of teaching design on acid-base and salt.By analyzing the teaching design strategy,teaching objectives,the teaching design based on classification is carried out and put into practice.The data obtained are analyzed and sorted out.The sixth part is the conclusion,inspiration,and the innovation of the research.The research conclusions are as follows:(1)Through the survey,it is found that the overall classification view of students is relatively weak,especially the cognition of the ontology view of classification is really insufficient.Students can not clearly understand the classification concept of substances or reactions,which can easily get into confusion.After teaching intervention,the average total score of the experimental class students was significantly higher than that of the control class.Although there was no significant difference in the view of ontology and method of classification,the experimental class students were significantly better than those of the control class in the dimension of classification values.The students in the experimental class have a good command of the prediction part of the properties of unfamiliar substances,can transfer and solve unfamiliar situations by using the ability of classification.Based on the collation and analysis of high-level students and low-level assessment data,the teaching design under the construction of classification view has little influence on low-level students,which have a low reserve of basic knowledge.So they cannot properly mobilize the existing knowledge for analysis and transfer.(2)Compared with traditional teaching design,what are the characteristics of the teaching design based on classification view?From the perspective of the formation framework of classification view,the teaching design focuses on ontology view of classification,helping students to understand "the same material has similar properties"by setting driving questions.And it guides students to find the learned knowledge model,imitate the transference,solve the problem,then understand the significance of classification.(3)In the teaching process of acid-alkali and salt,which based on constructing classification view,it is easily seen that the students can analyze material and reaction from the perspective of classification,understand the fact that the meaning of "the same material has similar properties",relate "the new knowledge" to "the old" quickly for the comparison and analysis,which will lay a solid foundation on subsequent material classification view.