The enhancement of the current exam question difficulty quantification instrument had contributed to the construction of the difficulty evaluation tool for the extra exam questions pertaining to the chemistry elective exam. A quantitative assessment on the difficulty of the eight extra exam questions for the chemistry elective-exams from 2015 to 2019, which had taken place in Zhejiang Province, an experimental zone for the new Gaokao(National College Entrance Examination), was conducted. As shown from the quantitative assessment, there was a large difficulty variation in terms of the overall test questions. However, in the same academic year, the overall difficulty of two separate chemistry elective exams that may be taken by one student was relatively close. There was a significant difference in competency characteristics and difficulty of the extra exam questions. The extra exam questions for “Fundamentals of Organic Chemistry” (Question No.32) shared an identical difficulty, while the difficulties of Question No.30 (Theory of Chemical Reaction) and Question No.31 (Experimental Chemistry) displayed an obvious fluctuation. On the basis of analysis with regards to the difficulty and relevant factors of the eight extra exam questions, this paper had also put forward feasible suggestions for the improvement of the formulation of exam questions.

Based on the different functions of the tables in the current four versions of Compulsory Education Chemistry textbooks, this paper classifies them into four types: experimental record, table inductive summary, exercise and data card. The teaching functions of the four types of tables is analyzed and explained. Taking the textbooks published by Shanghai Educational Press as an example, this paper makes a sample survey and analysis on the current situation of junior middle school chemistry teachers using tables in textbook to teach, and puts forward three teaching suggestions.

This paper creates a real situation to review the theme with oxygen as the clue, explores the reaction between calcium peroxide and water, summarizes the ideas and device model of gas production, and migrates and applies them. Using the knowledge of metal and acid-base salt, this paper rethinks the experiment of measuring oxygen volume fraction in the air, looks for the idea of experiment innovation from the perspective of experimental device and drug selection, improves students’ ability of experiment exploration and innovation, and implements the core literacy of chemistry.

Based on the analysis of the connotation of “social responsibility” literacy and the current situation of research, this paper has formulated the goal of “social responsibility” literacy of junior high school chemistry “fuel and its utilization” review teaching course. It also designed the teaching process with the “change of comprehensive utilization of straw” and the “history of evolution” of fuel for the “historic fuelwood fuel- easy to use fossil fuels- clean and environmentally friendly new fuels”. From the perspective of “fuel and its utilization” review teaching, junior high school chemistry teaching can make students obtain social responsibility“experience to form social responsibility”literacy through real situations, innovative experiments and meaningful learning experiences.

Based on the investigation and analysis of the students’ existing electrolytic cognitive model, and taking the electrolytic saturated salt water as the research background, this paper inquires into why saturated salt water is used and why iron nails are used in the cathode, in order to break down the students’ misconceptions about the absoluteness and uniqueness of discharge sequence, and realizes that the discharge sequence of ions is affected by concentration, electrode material and electricity. Pressure and other factors have common influence. Questioning the scientificity of the cognitive model of ion migration discharge electrolysis, the students design experiments to analyze the experimental phenomena, and self-modify and optimize the redox discharge model to analyze the electrolysis problem, so as to realize the revision and reconstruction of the existing cognitive model of electrolysis.

The teaching based on evidential reasoning is a teaching that responds to the history of chemistry, points to the future and faces the present. Taking the teaching practice of “the properties and uses of oxygen” as an example, this paper illustrates the importance of evidence-based reasoning in teaching: it can help students to consolidate the basic knowledge of chemistry, master the necessary basic skills; form the basic chemical ideas, preliminarily understand the material world; master the scientific thinking mode, scientifically analyze and solve problems, so as to help students open the door of chemistry.

In order to overcome the difficulty of “chemical formula calculation”, the learning process and influencing factors of chemical formula calculation are analyzed based on the learning progression theory. Taking the influencing factors of chemical formula calculation as the dimension, the behavior performance of two expected levels of chemical formula calculation is described. In order to provide a case reference for the teaching of chemical formula calculation,the teaching design is carried out based on the problem of driving the design of students’ expected behavior.

This paper takes the flipped classroom “ethanol” as an example, with mind mapping as the main evaluation means and the way to represent the stage results. In the process of flipped classroom teaching, it promotes the cultivation of students’ core literacy.

In the Guide Inquiry Activity in AP Chemistry Classroom, the necessity of adopting inquiry teaching method for conceptual knowledge is clarified, and according to the theory of learning circle, four consecutive teaching activity stages are successively divided: concept inquiry, concept formation, concept application and concept evaluation, so that students can participate in the whole process of scientific concept formation. Taking the teaching content of “chemical equation” as an example, this paper introduces the relevant teaching theories and the inquiry teaching enclosed-loop formed on this basis, in order to play a certain reference role in the inquiry teaching reform of chemistry concepts in middle schools in China.

Through the observation and analysis of the teaching practice of “molecule and Atom”, the methods and strategies of chemistry concept teaching under the perspective of core literacy are discussed. The discussion holds that the interpretation and interpretation of chemical concepts should be based on students’ cognitive ability, and should follow the construction process of “abstract → concrete → abstract”, while multidimensional and profound participation is conducive to the high-quality construction of concepts.

In this paper, Meng Xi Bi Tan was tried to integrate into chemistry teaching of middle schools. The four chapters of Wu Xian River, Zhan Lu Yu Chang, Petroleum and Dan Fan Lian Tong are combined with chemical knowledge including colloid, alloy, petroleum fractionation and substitution reaction in the form of problem situation importing and questions compiling, to help students understand chemistry knowledge, cultivate the overall quality of students, and inherit excellent traditional culture imperceptibly.

To investigate pre-service and in-service chemistry teachers’ perceptions of teaching competence, a 5-points Likert-style measurement instrument was developed by authors basing on a subject teaching competence model previously constructed by the project team and was implemented to 112 chemistry normal students and 83 high school chemistry teachers. This instrument involves six dimensions, i.e., ontological, instrumental, conditional, practical, dispositional, and developmental components of teaching competence. Both multidimensional and unidimensional Rasch models were applied to analysis the data by using the ConQuest and Winstep software, as well as SPSS22.0 for further statistics. The results showed that: (1) the developed measurement instrument possess good reliability and validity; (2) pre- and in-service chemistry teachers consensually ranked dispositional, ontological, developmental and practical components the first to fourth important components of teaching competence; (3) pre-service chemistry teachers’ score on instrumental component was significantly higher than that of in-service chemistry teachers; (4) item maps generated by ConQuest multidimensional analysis visually demonstrated the importance order of elements within each dimension of teaching competence.

Chemical science books are important carriers for the dissemination of chemical knowledge and chemical ideas. Based on 74 chemical science books sold in domestic online book trading platform, this study made statistical analysis in five major areas: the number of publications, the author and reader community, the content type, the formal feature and the evaluations of users, and summarized the status of domestic chemical science books and found problems in them. Further, some suggestions were provided.

Based on the existing problems in the current teaching of ionic equilibrium in acid-base titration, a software for knowledge learning and exercises testing, taking strong alkali titrating weak acid as an example, is developed. The software demonstrates the dynamic changes in the titration process with visualized techniques, such as curve and histogram. Therefore, students can get information from the ionic reactions, images and data of the titration process, further recognize the intrinsic principle of ionic equilibrium in acid-base titration. The software can not only be used for teaching various concepts of ionic equilibrium, but also create necessary teaching situations for explaining related exercises.

The Periodic Table is an important tool for students to study chemistry issues. In addition to the periodic table provided by the textbooks, various online periodic tables have the potential to enhance students’ understanding of chemical elements and the basic concepts of chemistry. This article summarized the sources of various forms of online periodic tables and introduced their websites to provide resources for teaching. At the same time, for the periodic table providing a large amount of physical and chemical data, the Handbook of Chemistry and Physics is used as a standard to evaluate the data of four elements carbon, oxygen, iron and chlorine which are often found in the textbook, and provides effective reference for users.

In view of the defects of the demonstration device for measuring the chemical reaction rate in the middle school chemistry teaching materials, a gas velocity measuring tube is designed, which is combined with a double-layer flat bottom flask, a temperature sensor, a silicone rubber heating sleeve, etc. to form a temperature control velocity measuring demonstration device. Taking the reaction of zinc and dilute sulfuric acid as the object, the effect of temperature change on the reaction rate was quantitatively studied. The accuracy of quantitative research was improved by controlling the stability of reaction liquid temperature, controlling the maximum initial temperature to reduce the effect of water vapor, and selecting effective experimental data. It is concluded that the reaction rate of zinc and dilute sulfuric acid increases by 1.4 times when the temperature increases by 10 ℃. The discovery of problems, the design of instruments and the process of research are conducive to the cultivation of students’ questioning ability, innovative spirit and evidence awareness.

Digital hand-held technology was used to compare the coagulant water purification effect and study the water purification mechanism. That was, through the colorimeter and pH sensor from four major aspects the amount of coagulant input, water purification rate, pH adaptation and corrosion compared the water purification effect of three coagulants. The following conclusions were drawn: the water purification effect of PFS was better than that of ferric sulfate and alum; the optimal alum dosage was about 125 mg/L, and the optimum dosage of ferric sulfate and PFS were both about 75 mg/L. Finally, based on the tetra-representation teaching model, analyzed the pH curve of the water purification process and obtained the general mechanism of coagulant water purification.

The vacuum fresh-keeping box is used as an experimental device to measure the gas molar volume, and the pressure change of the experimental device is measured by the smart phone’s pressure sensor through the smart phone app Phyphox, so as to measure the gas molar volume under the normal condition. The experimental results show that the improved experiment has achieved good results, and the improved method is easier for students to operate.

The history of change in the concept of Mole runs through all the history of human development since modern chemistry. It is a key event in the change of scientific thinking in the history of chemistry. The scientific practice, thinking and decision-making behind its changes have profoundly affected the development of chemistry. Clearing the history of Mole’s definition changes helps to clarify the value of philosophy and history behind it for scientific understanding and scientific teaching. The study finds that the history of Mole’s concept development is divided into three stages: germination, development and maturity. It is a typical history combining scientific thinking with scientific practice. It contains rich scientific decisions. And argumentation is also an important material for student concept discovery and meaning learning.

This paper reviewed the papers related to the periodic table of chemical elements published in Journal of Chemical Education from 2009 to 2019, analyzed their characteristics in domain, audience, pedagogy, and then introduced representative teaching cases including model construction, learning by games, inquiry learning and cooperative learning etc.