This article deeply analyzes the main components,molecular structures and action mechanisms of organic and inorganic sunscreen agents,revealing a series of complex chemical reactions they undergo after entering the marine environment and the irreversible and serious damage of these products to the marine ecosystem. To maintain the ecological balance of the ocean,this article proposes coping strategies from three dimensions: strengthening supervision and encouraging research and development,developing environmentally friendly sunscreens,and product transformation and environmental awareness.

Conceptual understanding is an important topic in scientific education research. The confusion appeared in definition of conceptual understanding will make it difficult for teachers to effectively guide and promote understanding in teaching. Generative learning theory is a progressive theory that explains student learning based on information processing theory. From this perspective,it analyzes how conceptual understanding generated and how differences in conceptual understanding made,providing a scientific basis for promoting concept understanding in chemistry teaching.

The project focuses on the theme of “self made safety mining lamp”, integrating relevant content from history, physics, and other courses, leading students to retrace the path of scientist David. Firstly, the historical issue of gas explosions in mines in the 18th century is presented, guiding students to analyze the causes of explosions and explore the conditions of explosions using the idea of controlling variables. Then, students are inspired to design devices to collect hydrogen gas of different concentrations, measure the explosion limit of combustible gas hydrogen gas, and finally make safety lamps to test their explosion-proof effect. In the process of solving the real problem of mine explosion prevention, students learn and apply the knowledge of explosion, deepen their understanding of concepts, enhance their scientific exploration and practical abilities, and cultivate a scientific spirit of daring to be the first, rigorous and realistic, and daring to explore.

This paper has implemented the unit review with a focus on exploring the application of isotope labeling technology in medical treatment, which is a real problem. The correlation between the subject content and the course content is explored and the theme of the course content is realized. Design tasks and activities with disciplinary characteristics, thus playing the role of students’ subjectivity and promoting the transformation of teaching time and space from “limited closed” to “unlimited open”, and achieve the task-based theme content and independent task solution. At the same time of knowledge construction, the cognitive model of element “position-structure-property” relationship is developed into that of nuclide “position-structure-property” relationship, which is beneficial for realizing the structure of knowledge operation.

Writing lesson papers for secondary school chemistry teachers is an important requirement for their professional development,but there are many practical difficulties. To promote chemistry teachers’ writing ability of lesson paper,a district-level teachers’ continuing education course was developed using Liwan District,Guangzhou City,Guangdong Province as a practical base,with “acquaintances and facts” as the entry point and “Lesson Paper Writing Scaffold” (LPWS) as the tool. Participating teachers had a positive attitude towards the course. Middle school teachers had more significant positive attitudes towards organizational quality and usefulness of course than high school teachers. There was no significant difference in course acceptance attitudes among teachers with different professional titles. The application of Lesson Paper Writing Scaffold was the core factor for achieving teaching effectiveness in the course. Several suggestions for optimizing course design and practice in the future were given.

Chemistry achievement emotion is a critical non-cognitive factor, referring to the direct emotional experience of individuals in chemistry learning activities. Utilizing the achievement emotions scale and the chemistry self-efficacy scale, latent profile analysis was employed to examine the types of achievement emotions among first-year high school chemistry students opting for the subject. The analysis identified a two-category model as optimal: the high positive-low negative group and the mixed emotions group. Utilizing the robust three-step (R3STEP) method and BCH approach to establish a regression mixture model, it was found that male students were more likely to be categorized into the high positive-low negative group compared to females; furthermore, students with higher chemistry self-efficacy were also more likely to fall into the high positive-low negative group. Students in the high positive-low negative group exhibited significantly higher chemistry academic achievement compared to those in the mixed emotions group. Based on this, specific teaching strategies had been proposed for different emotional groups to develop students’ core competencies in chemistry.

The comprehensive exploration experiment on combustion conditions was innovatively designed using micro experimental instruments such as double tube and combustion tube in a gas experimental micro device, including three required experiments for junior high school students: oxygen production, carbon dioxide production, and exploration of combustion condition. It was proved that the innovative experiment had the advantages of environmental protection, safe, simple and so on through the teaching practice.

In this paper, soap was made from waste kitchen oil. Compared with the process flow introduced in the textbook, the experimental process was refined, which was more conducive to life, and the optimal experimental conditions were explored to improve the production efficiency. The optimized experimental results showed that the mixed acid with a ratio of citric acid to phosphoric acid of 1∶1 was added to the kitchen waste oil for degumming treatment, and then the saponification was carried out at a temperature of 60 ℃ and a sodium hydroxide concentration of 40%. The soap produced under this condition had the best decontamination effect and less time, only about 25 minutes were needed to remove the debonding time. This program would be promoted and implemented in high schools, so that students could feel the value of chemistry and the practical significance of “turning waste into treasure” in practical activities, and then cultivated students’ scientific inquiry ability and innovation awareness.

This paper used baking soda, household disinfectant vinegar (at a concentration of about 80%), coins, and other materials for kitchen experiments, making a homemade, reusable “breaking heat” hand warmer, which provided a new avenue for students to grasp the concepts of solutions, heat energy, and phase change.

With “exploring electrodialysis method for seawater desalination” as the main line, saturated salt water was selected as a substitute for seawater for electrolysis experiment. Purple cabbage was used as a unified indicator, and self-made teaching aid was gradually developed from membrane free to multi-cell and multi-membrane electrolysis of saturated salt water to explore the working principle, device design, maintenance and optimization of “membrane” of seawater desalination electrodialysis method. Help students to build a systematic analysis model of electrolytic cell, and experience the application of electrolytic knowledge in real industry. In the process of electrolysis, the color of solution in different electrolytic chambers presents different color indicators, and the dynamic transition and gradual change of color between different electrolytic chambers can effectively help students understand the pH change, ion movement and electrode reaction of different electrolytic chambers, and at the same time make up the blank of the lack of multi-cell and multi-film electrolytic cell electrolysis experiment in the textbook.

Through qualitative and quantitative exploration, the effectiveness of common reagents such as saturated lime water, sodium hydroxide, ammonia water, potassium carbonate, monoethanolamine, and N-methyldiethanolamine in capturing CO₂ was compared. Through experiments, the rate and balance of CO₂ capture were explored, and the capture effects of the aforementioned CO₂ capture agents were compared. The experimental setup is simple, the reagents are readily available, and the phenomenon is obvious. It can be used as a classroom demonstration experiment or a student comprehensive experiment.

The aldol condensation reaction is a commonly used method for extending carbon chains in organic synthesis and plays an important role in both production and daily life. The content related to the aldol condensation reaction was first introduced into high school chemistry textbooks in 2020. The article interprets the mechanism,selectivity,rate,conversion,and application in synthesis of the aldol condensation reaction from multiple dimensions such as structural chemistry, experimental chemistry,and principles of chemical reactions,reinforcing the chemical concept that“structure determines properties”.

Starting from the oxidizing properties comparison between concentrated nitric acid and dilute nitric acid in the college entrance examination questions, this paper expounded the fallacy of the current oxidizing property comparison. Starting from the concept of oxidability, taking the oxidability of nitric acid as an example, the evidence of oxidation strength comparison was sought from three aspects: structure, property and electrode potential. Through the comparison of the oxidizing strength of the same substance by changing conditions (concentration, pH, etc.), the idea of oxidation (reduction) properties comparison and its influence on redox reaction were explored from qualitative to quantitative.

By heating aqueous solutions of ammonium chloride and sodium bicarbonate of different concentrations, qualitative and quantitative analysis and theoretical calculations were used to explore their decomposition in aqueous solutions. In quantitative analysis, chemical precipitation method was used to calculate the decomposition rate of substances in real experiment situations, improving accuracy. The study showed that both ammonium chloride and sodium bicarbonate in the solution decomposed when heated with the inner flame of an alcohol lamp. The decomposition rate showed an increasing trend as the solution concentration increased. At the same temperature and concentration, and heated for the same time, the decomposition rate of ammonium chloride in the solution was lower than that of sodium bicarbonate. The research results had certain implications for the heating research of other ammonium salts and weak acid salts in aqueous solutions.

In response to the shortcomings in the experimental production of hydrogen oxygen fuel cells, guided by micro mechanisms, this paper integrated theory, technology, and materials to explore the core factors that affect the operation of batteries from three dimensions: source, process, and result. Using 3D printing technology to independently innovate and design a four-chamber device for a closed system, exploring one of the core factors, the amount and purity of H₂/O₂. Drawing on the research findings of the National Graphene Research Institute in the UK, a self-made mesh graphene electrode was developed using the Hummers method to explore the core factor of H₂/O₂ adsorption and catalysis. Self-made egg semi permeable membrane, exploring the core factor of resistance. To improve the energy supply rate, catalytic rate, and conversion rate. During the exploration process, hand-held technology was used for digital innovation experiments, and a quadruple characterization model was constructed to establish a systematic analysis approach for electrochemistry.

Science Teaching Orientation (STO) is an important concept within research related to pedagogical content knowledge (PCK),which plays a key role in both the development of teachers’ professional knowledge and classroom practice. The conceptual framework of STO is clarified by sorting out the lineage of STO conceptual development. On this basis,the review mainly focuses on three themes: from the perspective of professional knowledge,the interaction between STO and PCK and the impact on the development of both are analyzed; From the perspective of classroom teaching,the relationship between STO and teaching practice is explored,and the reasons for the inconsistency between teaching practice and STO are elucidated; And from the perspective of professional development,the influencing factors and developmental strategies of STO are clarified. The research review provides useful insights into the research in the field of STO and the professional development of science teachers in China.

After the outbreak of the Anti-Japanese War in 1931,in order to adapt to the domestic situation,the Ministry of Education held a chemistry seminar and proposed to increase the content of national defense chemistry in the secondary chemistry curriculum at that time. After the meeting,the national defense chemistry received general attention in China,and the chemistry textbooks of secondary education began to add chapters related to national defense chemistry. This paper systematically sorted out the chemistry textbooks for secondary education in the Republic of China period,conducted a systematic study on the content of defense chemistry in 25 kinds of middle school chemistry textbooks,analyzed the characteristics of the content of defense chemistry in the textbooks with the knowledge of gas,gas defense,gunpowder,combustion agent and fume agent as the core,and analyzed the characteristics of the exercises in this part after class. It provided useful reference and enlightenment for the integration of national defense education into the chemistry curriculum of secondary education.