A Study On The Evaluation Of Chemical Element View Of Grade Three Students In Junior High School

The Chemistry Curriculum Standard of compulsory Education(2011 Edition)clearly points out: as the initial stage of junior high school chemistry,we should arouse students' curiosity in learning chemistry,guide students to understand the changing laws of the material world,and form the basic concept of chemistry.Therefore,an important goal of chemistry education in middle school at present is to train students' basic concepts of chemistry,such as element view,particle view,change view,classification view and so on.Among the many basic concepts of chemistry,the concept of element,as the core of the basic concept,is the basis of the construction of other basic concepts.So the primary goal of chemistry education in junior high school is to cultivate students' view of chemical elements.The essence of various substances and their chemical reactions is deeply understood.It can be said that the concept of element plays the role of dominating the whole world in many basic concepts,and has the value of unified and lasting migration.Therefore,the construction of the students' view of elements is beneficial to the students to form an orderly understanding of the physical world and the thinking method of chemistry.On the basis of summarizing the domestic and foreign researches on the concept of elements,this study finds that the study of the "view of elements" in junior high school chemistry is mainly focused on the analysis of the system of constructing the concept of elements in the textbooks,as well as the methods and strategies of the construction of the view of elements,and most of them arespeculative.Empirical research,but from the perspective of quantitative and qualitative investigation and empirical research is less.Therefore,the study of chemical element view of junior high school students is of great significance in teaching and education.Combined with the actual situation of junior high school chemistry teaching,the concept of "element view" in junior middle school chemistry is operated,and the basic content of chemical element view in junior middle school is divided into 3primary indexes and 15 secondary indexes,and the evaluation system is established.And according to the evaluation and the evaluation index system corresponding to the "junior high school chemistry 'elemental view' development level test paper"(test tool,Zengcheng District Sanjiang No.1 Middle School),A total of 372 students from Sanjiang No.2 Middle School and Licheng No.3 Middle School were tested.Using the principles and methods of educational statistics,the present situation of the construction of the elementary view of junior high school students was described quantitatively and qualitatively,and the following conclusions were obtained.On:The reliability,validity,difficulty and differentiation of the three primary indexes were 0.86?0.82 and 0.85,0.63,0.48 and 0.58,respectively.The results showed that the test instrument was not only in dimension division but also in overall quality,and the reliability was 0.33,the validity was 0.63,the average difficulty was 0.48,and the average differentiation was 0.58.Both have good reliability and accuracy,and the difficulty is moderate,can play a good role in identification.The average score of 372 subjects was 52.12,the standard deviation was23.22,the number of students below 60 points was 241,accounting for 64.78 percent of the total,and the number of people below the level of knowledge or below was207,accounting for 55.65 percent of the total.The development level of element view of most junior high school students is at the lowest level,the construction effect of element view is not good,and there is great room for improvement.At the confidence level of 0.05,there is a significant difference in the development level of the concept of element among male and female students: the total score of female students in the evaluation of the concept of element and thescores of each grade index are higher than that of the boy.It is shown that girls are significantly higher than boys in the overall understanding of the concept of elements or in the recognition of the first level of indicators,while students with learning difficulties have a significant foundation in the overall understanding of the concept of elements and in the understanding of each level of indicators,all of which are significantly lower than those of excellent students at school.The key points of the first order index response of all the subjects are "understanding of elements" and "studying matter from the angle of element",and the heavy and difficult points of the second order index are all "simple calculation of chemical equation".Through the investigation of students' chemistry learning motivation,we can know that the internal cause of sex motivation is directly affected by three factors,the degree of influence from small to large is the chemical values,the sense of self-efficacy,the attribution of success or failure.The attribution of success or failure and the sense of self-efficacy directly affect academic achievement.This research through the data analysis,understands the junior middle school student element view construction present situation,the analysis indicated that the junior high school student has the following question in the element view construction aspect: first,to the knowledge aspect study is still uses the mechanical method,Chemical knowledge is not actively refined and processed.Secondly,there is no habit of understanding matter from the perspective of elements.In the analysis of a substance,it is limited to the specific properties of matter,not to the material and its constituent elements.Third,for chemical reactions,there is no real grasp of the nature of chemical reactions,nor are they confined to specific chemical reactions.The substance of the reaction extends to all chemical reactions.Based on the conclusion of the research,and according to the author's teaching practice,This paper puts forward the strategy of chemistry teaching based on concept construction: 1)the construction of chemical element view should attach importance to the education of the history of element concept development to students and the construction of chemical element view should strengthen thestudents' ability of induction and comparison.The construction of the concept of element should be based on simple content.In order to reduce the difficulty of learning,we should dig deeply into the connotation of chemical experiment and strengthen the construction of chemical experiment teaching.Teachers need to have the concept of lifelong learning and pay attention to the present educational idea.Change the traditional teaching mode.