The chemical science thinking of understanding, thinking and solving problems like chemists was regarded as an important sign of forming the core literacy of chemistry discipline. Based on the thinking perspective of problem solving, the concept of chemical science thinking was defined, and then the connotation of chemical science thinking was clarified by illustrating the chemical science thinking mode connected with macro and micro, and the chemical science thinking method of evidence reasoning and model reasoning. On this basis, the psychological mechanism and cultivation path of chemical science thinking were put forward.

The literature review of the understanding of chemistry discipline reveals that scholars do not share a common idea on the objects of the understanding of chemistry discipline, and there is an inconsistency relating to this issue. Based on that, the paper carefully examines the main ideas in the literature and finds that all the objects mentioned in previous studies can be grouped into three categories: chemical knowledge, history of chemistry, philosophy of chemistry; nevertheless, there still lacks an awareness and a systematic perception of a philosophy of chemistry. Therefore, the paper presents an analysis of philosophy of chemistry itself, theoretical foundation and essence of chemistry teaching, and the “supply and demand” relationship between chemistry teaching and the philosophy of chemistry. Then it further discusses the feasibility, rationality, and necessity of organizing the objects in the understanding of chemistry discipline from the perspective of philosophy of chemistry. The paper finally argues that philosophy of chemistry can work as a systematic and reasonable approach to de-structure the various dimension in the understanding of chemistry discipline, and also be an effective way to promote the subjects' understanding of chemistry to a profound and systematic level.

Achieve consistency analysis tool analyzes the consistency between evaluation and curriculum standards through three dimensions of centrality, challenge and balance, as well as six indicators including content centrality, performance centrality, source of challenge, level of challenge, balance and range. By using Achieve consistency analysis tool, this paper analyzes the consistency between the after-school exercises in chapter 7 “organic compounds” of Chemistry Volume Ⅱ (Compulsory) of the 2019 PEP edition and the relevant content under the subject “simple organic compounds and their applications” of the compulsory course in the curriculum standards, obtains the consistency of exercises and curriculum standard in different indicators. According to the research results, some suggestions are put forward for the revision of curriculum standards, the optimization of textbook exercise design and the evaluation of chemistry learning.

Based on the analysis of the subject content and function value of the newly designed “research and practice” column in senior high school chemistry textbooks published by People's Education Press, in view of how to give full play to the teaching function and value of this column and develop students' chemical core literacy, this paper puts forward the implementation strategies of creating teaching situation clue, developing research-based learning subject, developing school-based elective course and developing STEM course.

The arrangement of textbooks has its internal logical, and visual representation is an important part of textbooks, so the selection of visual representation should also follow certain principles. In this study, Gkitzia and others' analytical framework was used to conduct coding analysis on the visual representation of “material structure” related content in PEP junior and senior high school chemistry textbooks. On basis of the analysis of the representation type and function distribution, combined with the arrangement of knowledge about material structure in textbooks and the law of students' cognition and psychological development, this paper makes a profound discussion. It is found that the distribution of visual representation in PEP textbooks is consistent with the “three sequences” principle of textbook arrangement, and visual representation can be selected according to the characteristics of different phases and students. Finally, some suggestions on the compilation and use of visual representations in textbooks are put forward.

This article explores the teaching practice of “metal anti-corrosion”,focusing on the application of electrochemical anti-corrosion methods. As choosing “anticorrosion of carbon steel inner tank of electric water-heater” as the task situation, STEM education idea has been penetrated to promote the combination of knowledge and social life, and cultivate “questioning” sense and innovative spirit. At the same time, through the experimental research, the cognitive model of “electrochemical anti-corrosion” has been constructed, and then applied to solving the real industrial problem how to carry out the anti-corrosion design of inner tank of water-heater. During the progress of solving real situation problems, knowledge, method and application has been well integrated and then transformed to the core competences of chemistry gradually.

Electronegativity is an important concept of the module “structures and properties of matter” which belongs to chemistry optional compulsory course in senior high school. This lesson uses the “project-based learning” approach. In the process of experiment, through analysing, discussing the harm and removal of formaldehyde, it can enhance students' understanding of electronegativity and mastering the method of using electronegativity to analyze and predict the chemical properties of substances. At the same time, it can help students experience the use value of the concept of electronegativity.

In the teaching design stage, firstly, the understanding research of atomic structure discipline is carried out. By explaining the two original problems of how to understand the composition of atoms based on the atomic nucleus and how to understand the structure of atoms based on the movement of electrons outside the nucleus, the atomic structure model of large concepts of the subject discipline is understood in an original and structured way. Then, from the aspects of teaching objectives and teaching ideas design, teaching implementation process, students' harvest, teachers' reflection and expert evaluation, this paper systematically presents the research process of “competence-oriented” and “exploring atomic structure based on scale” classroom teaching based on discipline understanding.

Based on the review characteristics of organic chemistry in senior three, taking the real situation as the carrier, this paper sets questions with different comprehensive complexity, and guides students to predict the material structure and design the transformation route from the perspective of the transformation of functional groups of organic compounds. This paper guides students to understand the reaction process from the perspective of the change of carbon skeleton and chemical bond, and understand the relationship between the type and polarity of covalent bond and organic reaction. The separation and purification scheme is designed by using physical properties, which reflects the integration within the discipline, and enable students to truly establish the basic concept of “composition and structure determine nature”, highlight the problem-solving ideas of organic inference such as comparative analysis and inverse synthesis analysis, develop high-order thinking, promote the improvement of students' key abilities and promote the development of core literacy of chemistry.

Aiming at the problems existing in the current homework design, this paper studies the situational homework design. The paper deals with the definition and current use of the chemistry situational homework in high school in the first place, followed by the clarification of its design fundament, illustration of four principles and the proposal of six procedures. Then, an example of the situational homework is given on the basis of the unit of “hydrocarbon derivatives”, reflecting the integration of teaching, learning and evaluation.

Project-based learning is one of the effective approaches for competence-based chemistry classroom teaching. The design of driving questions is a fundamental vehicle for supporting the effective implementation of PBL instruction. Driving questions could drive and organize an entire project that could foster students' development of asking questions, drive students engaging in project, and guide students solving real-world problems. Using “ionization and ionic reaction” as a case, this study illustrates the categories and function, design principle and design process and practice of driving question. This study brings new insights for chemistry teachers and researchers on how to design high-quality driving questions in PBL instruction and on how to implement driving questions in classroom teaching.

Using historical facts related to the formation and development of human knowledge about carbon dioxide as question clue and main teaching thread, the teaching situation was designed, in which the history of science was utilized to help improve students' general understanding of properties of carbon dioxide and facilitate them to preliminarily establish a basic route and method to learn everyday substances. The study provided a reference for classroom teaching of chemistry teachers in junior high schools.

The solution of complex computation problems in junior high school chemistry involves the mental process of information processing, such as information extraction, model construction, algorithm application, etc., which highlights the characteristics of chemical thinking, such as foundation, comprehensiveness, systematicness and complexity. It is of good value to cultivate the core qualities of chemistry discipline, such as macroscopic identification and microscopic exploration, change concept and balance thought. The adoption of multi-perspective cognition, sub-skill training and the three-stage adaptive training and learning guidance model of “adaptation, ability and mastery” can effectively improve the success rate of learners to solve such problems, and lay the necessary literacy foundation for learners' subsequent learning.

In order to reveal the key characteristics of teacher-student behavior interaction under the “high-end lesson preparation” project, the video analysis method and lag sequence analysis (LSA) are used to quantitatively and qualitatively analyze the teacher-student interaction behavior, ratio, teacher language, teacher-student operation technology and the interaction behavior between teachers and students in the “ion reaction” classroom in the high-end lesson preparation project in 2019. The study finds that high-end lesson preparation pays more attention to students' scientific cognitive logic of original cognitive problems, takes teaching core concept construction and based on students' cognitive development as the concept, changes from knowledge analysis to promoting students' cognitive development, and promotes students' knowledge transfer and application through the process of continuous collision between teachers and students, and it provides a reference path for normalized classroom optimization.

The “inspection of iron in food” experiment has been added to the 2019 People's Education Edition senior high school chemistry textbook compulsory one, according to this experimental scheme, iron in spinach was detected, but experimental phenomena could not be observed obviously due to pigment interference. In view of this, the color transmittance of the extraction solution after color development was used as the index to evaluate the experimental effect, and the control variable method was used as the experimental method. The common iron-containing food, iron extraction method, extraction time, concentration of hydrochloric acid in the extraction agent and the amount of the extraction agent were optimized. The optimized experimental results showed that 2 g bean tendon and 20 mL hydrochloric acid with the concentration of 4 mol/L were stirred by the wall-breaking machine and extracted for 5 min, and the color value of the extract was 62%, showing a good blood red. It can effectively prove the existence of iron in food and has obvious experimental phenomenon. It can be well applied to teachers' demonstration experiments and students' group experiments.

Based on the abstract knowledge teaching of atoms and molecules in high school chemistry, this paper discussed the application of modern analytical instruments in high school chemistry teaching by taking the experiments of sunscreen protection effect as an example. By using the modern analysis instrument UV-Vis spectrophotometer to explore the sunscreen protection effect, analyzed and mastered the chemical sunscreen mechanism combining with the ultraviolet discolor-changing ball experiments. The results showed that the greater the thickness of the sunscreen and the higher the SPF, the better the protection effect of the sunscreen, the sunscreen could last for a period of time, but there were some differences between different types of sunscreen products. The applications of modern analytical instruments in chemistry teaching would lay a solid foundation for students to further understand the chemistry discipline in changing the learning way, broadening the field of subject knowledge, and promoting their comprehensive and sustainable development.

Several scales of metallicity are briefly analyzed, and a more applicable electronegativity scale is introduced; the concepts of electron affinity energy and electronegativity are analyzed to clarify students' cognition of the most metallic and nonmetallic elements. At the same time, the teaching methods of element periodic law and alkali metals in compulsory 1 of PEP are proposed.

Litmus solution doesn't change colour obviously in alkaline solution,which annoys our experimental teaching activity all the time. By applying mobile phone's software: color recognizer,digital sensor and other hard&soft ware technologies, this paper explored the selection of litmus reagent, optimization of preparation method and adjustment of pH of solution, trying to prepare a litmus solution that shows the obvious color in acid and alkaline solutions.

This paper analyzes and compares the publication, key words and research features of chemical kinetics in high schools published by Journal of Chemical Education (JCE)in the United States, Chemistry Education Research and Practice(CERP) in the United Kingdom and Chinese Journal of Chemical Education in China from 2011 to 2020, in order to provide reference for domestic chemical educators. Generally speaking, the three journals have different research focuses on high school chemical kinetics, JCE focuses on innovative experimental research, CERP focuses on learning research, and Chinese Journal of Chemical Education pays more attention to teaching research.

Based on the CiteSpace software, this paper uses knowledge graphs, keyword clustering analysis and other methods to analyze the current research status and frontier hotspots in the field of chemical triple representation in my country, visualize the information, and provide help and reference for Chinese scholars to further improve the research of chemical triple representation and expect to embed the thinking and strategies of chemical triple representation into the daily teaching.