Design And Practice Of Chemistry Teaching Based On Model Cognition

The international society is in the stage of rapid development nowadays.and the demand for talents is increasing day by day.In order to meet the needs of social development.raise the level of national competitiveness.and train all-round modern socialist talents.The ministry of education has launched a Revision of the Curriculum for ordinary high schools.In 2017.the ministry of education issued the curriculum standard for ordinary high schools(2017 edition)in order to develop the Key Competence of students.From then on.the Key Competence as a discipline guide guides the teaching process steadily.Evidential reasoning and model cognition is one of the five dimensions of high school chemistry Key Competence.As a combinatorial vocabulary,model cognition first appears in Key Competence,which can be understood as model cognition or model-based cognition.Model cognition is divided into four levels under the chemical core accomplishment,from the simplest model to understand and describe the model,to evaluate and improve the model,to build the model to solve the problem.The four different levels of model cognition are reflected in the teaching process,that is,the students' model cognition ability,and they also have four levels of ability,which are cognition,comprehension,evaluation and construction.The content of chemistry elective course 3 in high school is known for its micro and abstract,which contains a variety of model thinking and skills,and is the "main field" for cultivating students' model cognitive ability.After an in-depth study of the textbook and an in-depth interpretation of the course objectives of elective 3,the author conducts a teaching design for some chapters of elective 3 based on the improvement of model cognitive ability.The teaching design is still based on the teaching material content,but unlike regular teaching,the author will refine ideas contained in the classroom content of model,refined into classroom main clue,through,guides the student to know and understand the model and the model designed by the authors is used to solve practical problems,to strengthen the effect of classroom learning,at the same time,students' cognitive model.Before and after the implementation of someexperimental classes,the author also designed corresponding questionnaire and interview questions for the purpose of measuring the changes of students' model cognitive ability and their mastery of target knowledge before and after the teaching,and at the same time,overcoming the learning obstacles in the third elective course and improving students' model cognitive ability.Before and after teaching,the author measured the students' knowledge level and the dimensions of model cognitive ability by means of questionnaire and interview.The results of the investigation show that the teaching process based on the model cognitive ability design does have certain effects on the mastery of knowledge and the improvement of the students' model cognitive ability.In the course of teaching about the properties of molecules,The "electron vector model" designed by the author successfully helps students understand the relationship between the polarity of molecules and the polarity of chemical bonds,and teaches them how to correctly judge whether a molecule has polarity or not;The "hydrogen bond chain model" can also help students to understand the practical significance of hydrogen bond and how its existence affects the properties of materials.At the same time,this effect is not the same in different levels of student groups.The teaching design based on model cognition can play a positive role for students with relatively good foundation in the teaching process and help them understand and solve the deeper problems in the elective course.For students with a relatively weak chemistry foundation,it is also a good tool for solving problems.It can simplify the complex problems in elective course 3 and improve students' problem-solving efficiency and quasi-clustering.it is also found that the learning effect of the three elective stages is significantly positively correlated with the level of model cognitive ability of the students,and the in-depth learning process of the three elective stages will promote the improvement of model cognitive ability of the students,and the improvement of model cognitive ability of the students will in turn promote the learning effect of the three elective stages,which complement each other.