Cultivation Of Middle School Students' Particle Concept Based On The Triple Representation Of "Macro-Character-Micro"

Chemistry,as a science,studies substances at the microscopic level of molecules,atoms,and atomic groups.It is closely related to people's daily life,such as food,housing,transportation,agriculture,forestry,and medical treatment etc.Therefore,particle concept is important to recognize and understand the nature of substances.Particle concept,as one of chemistry concepts in middle school and an important part of the chemistry core literacy,has great significance for cultivating students' discipline literacy.The characteristics of mutual conversion among the concept of macro,micro,and symbols make chemistry learning different from other scientific subjects and make chemistry teaching should integrate macro,micro,and symbols with each other.In addition,cultivating the microscopic thought for students can help them make sense chemistry knowledge and increase their interest in learning chemistry.Through questionnaires,the opinion of local chemistry teachers on the particle concept,triple representations,core literacy and other related content are investigated and analyzed;the development of students' particle concept level ability is assessed via questionnaires,interviews,and semester tests.The results of teacher`s questionnaires show that the teachers slightly understand of core literacy,particle concept,and triple representation;the correlation between the three representations shows that teachers' cognition of the "macro-micro-combination" in core literacy is positively correlated with teachers' cognition of particle concept and triple representation.How to help students build the connection between the microstructure,the macroscopic properties and symbols is difficult to teach in the junior middle school.Based on the analysis of the teaching methods about how teachers break through the difficulty in chemistry teaching,we put forward some suggestions on teaching strategies,including the overall knowledge,each student,exploratory thinking and teaching language.The investigation shows that the teaching method based on triple representation is helpful to the cultivation of students' particle concept.It can be clearly seen that the understanding of microscopic knowledge of students in experimental class was significantly better than that of the control class.Comparison of the test score of the two classes at different stages displays that the teaching method based on triple representation has the most obvious effect on the middle-level students in the experimental class.Teaching methods,such as connection to life,model cognition,experiment exploring,and knowledge networks can overcome the difficulties of teaching and help students construct particle concept.At the same time,the thesis also provides instructional design for the teaching of particle concept which is helpful to middle school chemistry teaching.