Diet drinks are increasingly available on the market, but little is known about the sweetness in diet drinks. This paper briefly introduces sweeteners and their classification, the use of sweeteners in sugar-free beverages, and the effects of sweeteners on human body, in order to improve people's understanding of sweeteners in sugar-free beverages. Among them, the effect on human body is mainly aimed at seven sweeteners commonly used in diet drinks.

It is widely believed in the field of science education at home and abroad that the coordinated development of scientific concepts and scientific practices is an important way to cultivate students' scientific literacy. The arrangement and processing of the teaching materials for chemical required experiments have an important influence on the teacher's teaching design and implementation. This article briefly introduces the connotation of the coordinated development of scientific concepts and scientific practices, and conducts an in-depth analysis of the overall situation and specific strategies of chemical required experiments compilation in the compulsory senior high school chemistry textbooks of Beijing Normal University “New Century” Shandong Science and Technology Press. And explains how the textbooks compile chemical required experiments reflecting the coordinated development of scientific concepts and scientific practices, highlighting the core literacy development function of these experiments, and puts forward the teaching suggestions for the implementation of the new textbooks' chemical required experiments.

The reform of basic education curriculum emphasizes the inheritance and promotion of excellent Chinese culture, and evaluation is an important means to test whether excellent cultural education is effectively implemented. This study preliminarily constructed an evaluation framework for excellent traditional Chinese culture, and used this framework to analyze 38 sets of chemistry test questions for the 2021 national high school entrance examination in various provinces and cities. It had found that the proportion of high school chemistry test questions currently examining excellent Chinese culture was relatively high, with a wide coverage of test content and diverse question types, which could reflect a positive guiding role. At the same time, in response to the lack of depth in cultural examination in the current evaluation, suggestions were proposed to deeply explore cultural connotations and examine cultural literacy.

Taking the Chemistry Curriculum Standard (2022 Edition) for Compulsory Education of China and the chemistry test questions for 2020-2022 Guangdong and Guangzhou senior high school entrance exams as the research objects, the SEC consistency analysis model was used to examine the consistency between the 2020-2022 Guangdong and Guangzhou chemistry senior high school entrance exams and the new junior high school chemistry curriculum standards. On the basis of sorting out the proportion and difficulty of content themes and cognitive levels in the new curriculum standards for junior high school, this paper had an insight into the changing trend of the chemistry test question in Guangdong Province and Guangzhou City, hoping to enlighten the chemistry test proposition and teaching in the junior high school under the background of the implementation of the new curriculum standards.

Taking “comprehensive recovery and utilization of pyrite cinders” as the project learning theme, taking the preparation of copperas from pyrite cinder, and carrying out qualitative detection and quantitative composition determination as the project learning activities, this paper presents project learning and implementation process. Through the solution of real problems, the project-based teaching cultivates students' core competence and promotes in-depth learning.

On the basis of the preparation of a certain solute mass fraction solution in junior high school, the teaching was designed and organized with the idea of “contextualization-de-contextualization-re-contextualization”, which not only trained the experimental skills of substance concentration preparation, but also paid more attention to the development of students' scientific attitude and awareness of inquiry. The key to solving problems was transformed into disciplinary methods through context-induced problems and de-contextualization. Finally, disciplinary methods were transferred and applied to solve new problems in unfamiliar and complex situations. The teaching implementation went beyond the simple skill training, expanded the idea of higher order thinking of students, and highlights the rigorous and realistic scientific attitude. In addition, the exchange of cases of accurate measurement deepened students' recognition of the value of the subject.

The chemical argumentation teaching is conducive to improve students' key competence of evidence reasoning.By using hydrogen detector in “sodium” teaching,quantitative detection data of hydrogen,the reaction products of metal sodium and water,can be safely and effectively visualized. Moreover,the effectiveness of the argumentation is also promoted with images using to collect energy conversion information,and the projection of Hong-he screen and Seewo platform live broadcast function to present the intuitive evidence of experimental phenomenon in hydrogen test and energy change on the whiteboard.This class also introduces picture materials that are highly consistent with the thermal imaging pictures collected in the experiment: infrared thermal image images in the process of metal sodium tumor injection,creating rich scene materials to strengthen the argumentation,and highlight the value of chemistry discipline.

The traditional class only focuses on the semantic memory of macro-meaning, micro-meaning, and quality-meaning of chemical equations, and cannot reach the goal of deep teaching. This lesson clarifies the students' cognitive logic, analyzes the current teaching situation, and uses data images to let students find that there is a positive proportion relationship between the quality of various substances in chemical reactions. It helps students to summarize the information involved in chemical changes and gradually go deep into the micro level, excavate the essence of the macro quality relationship before and after the change, and finally quantitatively understand chemical changes and establish their own symbolic representation.

The new curriculum standards clearly state that the teaching of chemistry should stimulate students' interest and ideals in chemistry as a major and career. Taking the socio-scientific issue of “nitrogen pollution control in sewage treatment plants” as an example, a professional teaching framework for chemistry based on socio-scientific issues was developed, and four teaching processes of identifying topics, evaluation schemes, scientific debates and decision-making reflection were established, guiding students to understand water treatment related majors and occupations based on literature and websites, establishing professional confidence in the field of chemistry in debate and decision-making, and putting forward three suggestions for career education in chemistry based on practical results.

After studying the history, cutting-edge applications and learning situation of intermolecular forces, learning progress of intermolecular forces, flowchart of overall teaching plan, real situations and instructional designs are designed to cultivate key competencies and core literacies of students. The study concludes that teachers' deep subject understanding and accurate assessment of students' levels are basis for designing learning progress. Select teaching situations contributes a lot to promote the progress of students'key competencies and core literacies. And the use of physical models and metaphors is an important way to facilitate students' learning progress.

On the basis of describing the evolution of the concept of activation energy, and based on the problems and difficulties in its teaching, this paper puts forward the use of teaching software to construct the knowledge model related to activation energy, taking the reaction of hydrogen with chlorine as an example, driven by the problem chain, students can actively explore and understand the concepts of elementary reaction, activated molecule, activation energy and effective collision. It is proved that this method can effectively break students' existing misconception, help students establish concepts and models related to activation energy, and then understand and explain the factors affecting the rate of chemical reaction from the perspective of energy.

The big ideas of subject are the core of the whole unit teaching design. This paper analyzes the current teaching situation from the teaching content, learning situation and test questions, constructs the discipline big ideas based on the curriculum standard, discipline essence and students' cognition, and carries out the teaching design and practice of senior three organic review under the guidance of the discipline big ideas, so as to promote the development of students' core competencies of chemistry discipline.

Recently, inquiry-based teaching is becoming one of the hot spots in education and teaching reform and research own to its emphasizing of student-centered, concerning of the needs of students' exploration, and conformance of the concept of new curriculum reform. In order to analyze the effect of inquiry-based teaching and reveal its advantages, the present study performs a quantitative analysis of relevant literature utilizing the meta-analysis method and focuses on the research of inquiry-based teaching in the past decade at domestic and abroad. The results show that the effect size of inquiry-based teaching is 0.744, and the confidence interval is 0.552<ES<0.935, which are in the upper-middle level. In chemistry learning, the capacity of samples shows a significantly negative impact on the teaching effect of inquiry-based teaching; The difference between countries plays a crucial role in effect of chemistry learning; The implementation of inquiry-based teaching shows a better effect in high school. Based on the results of meta-analysis, it is recommended to carry out inquiry-based teaching actively and effectively in chemistry learning, thus enrich the content of chemistry courses and promote the effect of chemistry learning.

This paper introduced the main interface of Science Journal App software, and explored the influence of pressure on chemical equilibrium with the experiment of “transformation of NO₂ and N₂O₄”, the phenomenon was intuitive and obvious, which avoided the limitation of visual observation and improved the accuracy of experimental results. It provided a new path for information technology-assisted chemistry experiment teaching.

Based on RAMP paradigm, this paper explored the cultivation of risk perception and decision-making ability in high school chemistry experiment. According to the current status of risk perception education in high school chemistry laboratory teaching, this paper constructed the teaching mode of chemistry experiments, which incorporated the RAMP paradigm. And this study illustrated the way in which the four steps of recognizing hazards, assessing risk, minimizing the risks of hazards, and preparing for emergencies unfold in chemistry laboratory teaching with examples.

In this experiment, the device and external circuit of single-liquid and two-liquid primary batteries were designed using the controlled variable method and the combination method, and infrared thermography was applied to capture key evidence of heat generation sites. The experimental results demonstrated that the performance of the dual-liquid primary battery was superior to that of the single-liquid primary battery in terms of maximum output current, discharge efficiency and current stability, all other conditions being equal. Thermal images and precise temperature measurements obtained with a thermal imager revealed the main reasons for the difference in performance between the two primary batteries: the negative electrode of the single-liquid primary battery had a side reaction, and the internal resistance of the two-liquid primary battery was lower.

Addition reaction of ethylene with bromine is a very important reaction type in high school chemistry, and it is also a case of experiment inquiry in chemistry classroom teaching. This paper discussed the defects of experimental inspection schemes represented in various literature and proposed an improved experimental design, which was to test the acidity of the upper aqueous solution with pH paper, or to test the existence of Br^- with the upper aqueous solution.

This paper attempts to use the arrow-pushing method commonly employed in organic reaction mechanism illustration to explain reaction mechanisms of hydrogen peroxide including acid-base reactions with water and ammonia, reduction by sulfurous acid, sulfites, nitrous acid, hydrobromic acid and ethanol, oxidation by chlorine, Ce(IV) reagents or potassium permanganate under acidic conditions, as well as decomposition reactions catalyzed by light, base, anions and metal cations/complexes.

Starting from reaction mechanism, this paper analyzed organic chemistry questions in the 36th National Chemistry Olympiad Competition (Preliminary), in order to deepen the readers' understanding of the competition questions, understand the change law of organic chemistry, master the answer methods and skills, and improve the learning or teaching efficiency.

At the end of the 18th century, French chemist Lavoisier predicted that soil material such as lime were not simple substances. In the early 19th century, the British chemist Davy used electrochemical technology to prepare a new metal from lime and named it “Calcium”. The concept of calcium element was initially formed. Subsequently, with the advancement of the atom theory and the determination of the atomic weight of calcium, the concept of calcium had been developed. By the 20th century, the discovery of calcium isotope had given people a new understanding of the concept was calcium. In short, development history of calcium concept was not only the elements concept progressive process, but also the evolution history of scientific thought and scientific methods.