High Efficiency Teaching Practice Research Of "the Mystery Of Material Composition" In Junior Middle School Chemistry

"The mystery of material constitution" is the core content of junior middle school chemistry, including four aspects:chemical substances diversity, particulate matter, understanding of chemical elements and the composition of the material. It’s very important for students as it covers nearly half of the contents of junior middle school chemistry. This part of the content is relatively abstract. Students perceptual knowledge is not enough and out of life experience. This has brought a barrier to the study of the new knowledge.In studying this content, there is a big difficulty in the world of macro material into the world of particles. At this stage, the students had a distinct stratification, at the same time, it raises the difficulty of teaching.Therefore, chemistry classroom teaching should reflect the basic concept of efficient teaching, which can make the teacher’s "teaching" become "efficient teaching", make the students "learn" into "easy to learn". The"effective teaching" guide students to learn easily, improve students’ scientific literacy, academic performance and learning interest in chemistry.Based on the above understanding, this research takes the important part of the junior middle school chemistry-the mystery of the material constitution as the research object, studied the following questions:(1) Knowledge points of the third unit "the mystery of the material constitution" in the junior middle school chemistry "nine grade" (2012 Edition).(2) Knowledge points of 2011 edition chemistry curriculum standard.(3) Students in the cognitive perspective of the elements of the knowledge of the difficulties.(4) In view of the students’cognitive difficulties, the teacher carries on the effective teaching design, and the practical effect.In order to study the above problems, this study is divided into two parts. In the first part, the first step is to analyze the education and teaching theory which is suitable for this research. The second step is to sort out the knowledge of the material composition, the knowledge points of the unit set up in the curriculum standard and analysis of the depth of knowledge. The third step is to analyze the students’ cognitive difficulties with the literature. The fourth step is to put forward the principle of efficient teaching. In the second part, the first step is to set up the comparison class according to the class conditions, and the basic situation of the pre test. The second step is to design and carry out practical research on the theory of constructivism, cognitive learning theory and teaching optimization theory. The third step, tests and interviews of the experimental class and the contrast class to analyze whether the students can break through the cognitive difficulties through the implementation of effective teaching design.Through the above research, the analysis is as follows:(1)The new curriculum standards for this part of the content of cognitive learning objectives can be divided into three levels:the first level involved in the cognitive learning target verbs have to know, remember, say, find; The second level involves understanding, understanding, and can be expressed; Third level involves interpretation, simple calculation.(2) Subject 1 Molecules and Atoms includes matter is made up of microscopic particles and molecules can be divided into atoms. Subject 2 Atomic Structure includes structure of atoms,arrangement of atom, relative atomic mass. Subject 3 Elements includes Element, element symbol, and element periodic table.(3) The students completed the three levels of cognitive learning objectives, the first level of cognitive goals is easier to achieve; second levels of cognitive performance in the implementation of the general; in the course of the third levels of cognitive level, the performance is poor.(4) The students in the experimental class were better than the contrast class in the study of the students’ learning interest and learning effect by the analysis of the students’ interviews, the classroom experience questionnaire and the results of the third unit tests.