This paper briefly summarizes the biochemical mechanisms of energy metabolism, muscle repair and recovery regulation in fitness exercise from the perspective of molecular chemistry, and shows the dynamic chemical network constructed by the human body under exercise stress, which fills the gap in sports chemistry research and aims to provide a theoretical basis for scientific fitness.

Microplastics are widely found in water, soil, and the atmosphere, posing multiple threats to ecosystems and human health. Currently, technologies for identifying and managing microplastics remain limited, while the development of alternative materials and policy regulation also face challenges. In Tibet, microplastic pollution has become increasingly prominent due to human activities, atmospheric transport, and plastic aging, with its sources distinguished by unique regional characteristics rooted in local religious culture, such as the use of prayer flags and khata scarves. Taking microplastics as an entry point, this study aims to explore a path for integrating “ethnic culture, regional characteristics, and science education”. It discusses specific approaches to incorporating environmental protection education into high school chemistry teaching, with a particular focus on the status and control strategies of microplastic pollution in Tibet. The goal is to provide theoretical reference for integrating microplastic pollution prevention education into chemistry curricula and for implementing characteristic environmental education in ethnic regions.

The recognition of intrinsic questions of chemistry is an important process to realize the disciplinary understanding, and the implication of this is to take the essence of chemistry as the core, through the integration of structured knowledge system and the path of thinking progression, integrating multi-dimensional contexts such as historical traceability, social relevance, and experimental investigation, to drive the depth of disciplinary understanding and systematic cognition of the teaching practice. Its characteristics are reflected in the essentiality, development, hierarchy and contextual relevance. Its educational value is reflected in revealing the essence of chemistry, cultivating scientific thinking and problem-solving abilities in a historical context, driving students' thinking development, and achieving systematic understanding. And putting forward five design strategies:tracing the historical development of concepts and condensing intrinsic questions, constructing cognitive perspectives and cultivating intrinsic question literacy, considering cognitive adaptation and intrinsic questions progressing, contact with social life and intrinsic questions contextualizing, attention to the dynamics of scientific and technological development and intrinsic questions advancing, in order to achieve teachers to teach chemistry based on disciplinary understanding.

This study sorts out and analyzes the revisions of chemistry textbooks for senior high schools and compulsory education in both spring and autumn semesters over the past three years. It is found that the content of chemistry textbooks in basic education has achieved positive changes in aspects such as ideology, timeliness, scientificity, suitability, accuracy, and standardization. Looking ahead, the revision of chemistry textbooks should continue to strengthen their educational function, enhance evidence orientation, optimize the effectiveness of teaching and learning, deepen interdisciplinary collaboration, and promote digital transformation.

Chemical interdisciplinary topic learning is a crucial direction in the reform of the compulsory education chemistry curriculum. The regional venue resources are close to students' cognition, and developing interdisciplinary research courses with intuitiveness, distinctiveness and authenticity is conducive to the cultivation of students' chemical core literacy. Based on the interdisciplinary perspective, relying on the resources of the bicycle museum, with the development of bicycle metal materials as the main line, focusing on the theme of “civilization on two wheels”, the design and implementation of chemical interdisciplinary research courses are carried out. In the process of solving the driving problem chain and completing the task groups, the chemical discipline big concept of “properties determine uses” is implemented, providing a reference for the development and construction of chemistry interdisciplinary museum study courses.

The project takes the fun and interesting self-inflating firework gun as the carrier, integrating relevant contents from fields such as chemistry, physics, and engineering technology. It starts from the reason why the firework gun bulges, verifies the gas components produced, and then explores the “water packets” and powder inside. Finally, it uses the task of “making a self-inflating firework gun by yourself” to let students experience the process of making a firework gun. By making full use of driving questions, while reviewing acids, bases and salts, students' understanding of the concepts of the chemistry discipline has been deepened, their key abilities to solve practical problems have been enhanced, and the core literacy of the chemistry discipline has been comprehensively cultivated.

This article takes “self-made ink” as the real context, and sets four tasks: clarifying raw materials, exploring principles, improving applications, and evaluating achievements to carry out project-based teaching. It completes the unit review of “change and transformation of substances”, horizontally integrates the relevant unit knowledge in the junior high school chemistry textbook published by the People's Education Press, vertically connects the fivefold representation theory of “macro-micro-symbol-curve-model”, constructs a cross unit knowledge graph, and integrates the essence, characteristics, classification, laws, conditions, and values of material change through the “situation-problem-activity-evaluation” four in one teaching model. It moves from qualitative to quantitative, guides students to construct a conceptual system with material change as the core, uses conditional regulation to realize the value of change, transforms it into the target product, establishes a systematic cognitive framework for material transformation, and helps students to achieve advanced literacy.

The project is based on “determination of copper ion content in etching waste solution from copper-clad laminates using iodometry” as the main framework, which is further divided into three sub-projects: “establishment of the measurement principle” “optimization of the measurement process” and “application in real-world scenarios”. Through progressively structured experimental inquiry activities and micro-titration simulation experiments, students will review knowledge related to “ionic reactions and equilibrium in aqueous solutions” in practical applications. This approach helps them systematically construct a cognitive model for analyzing complex reactions in aqueous solutions, further developing their perspectives on particles, chemical changes, and equilibrium. Additionally, it enhances their ability to solve complex real-world problems, deepens their understanding of the value of chemistry as a discipline, and fosters the development of core chemistry competencies.

The project takes “exploring the all-vanadium redox flow battery” as its theme and conducts a special review of “electrochemical principles” for senior three students. In a real-life context, students deeply understand the electrochemical principles and construct a structured electrochemical knowledge system by completing four project tasks, namely “exploring the electrochemical properties of Vanadium” “designing an all-vanadium redox flow battery” “analyzing the electricity storage logic of the redox flow battery”, and “constructing an electrochemical cognitive model”. It achieves the review goal of transitioning from knowledge reproduction to ability improvement and provides a new paradigm for the electrochemical review of senior three students.

Based on the “competency-oriented” teaching philosophy, this study developed a cyanotype micro-project integrating chemical principles and artistic creation to enhance students' ability to solve practical problems in complex contexts. Through systematic experimental inquiry activities, students were guided to apply disciplinary knowledge to analyze experimental phenomena and regulate chemical reactions, achieving the integration of theory and practice while effectively fostering the development of higher-order thinking skills. Practice has demonstrated that this teaching model not only improves the effectiveness of review instruction but also cultivates students' interdisciplinary application skills and innovative awareness, providing a replicable practical case for interdisciplinary integration teaching under the project-based learning framework.

The teaching design incorporates key concepts such as “catalysts alter reaction processes and lower activation energy” “heterogeneous catalytic mechanisms involve three main steps: adsorption, surface reactions, and desorption” and “catalysts exhibit activity, stability, and selectivity”. It outlines three progressive class topics: understanding catalysts through the lens of “matter-energy”, deconstructing catalytic mechanisms, and evaluating catalytic performance. By creating a series of situation tasks, students are encouraged to build cognitive models that they can transfer to problem-solving scenarios, ultimately achieving advanced teaching objectives in the catalyst unit based on chemistry subject understanding and deep learning.

The organic compound structure recognition model innovatively integrates three aspects of organic compound structure understanding, namely R-G, chemical bonds, and electronic effects. This integration reveals the associative mechanisms and dynamic influences among different levels, providing an actionable analytical paradigm for understanding the properties of organic compounds and organic reactions. The application of this model can enhance the systematic understanding of the chemical properties of organic compounds covered in four sets of textbooks. Its three major functions, namely explanation, prediction and reasoning, as well as design and regulation, also hold practical implications in addressing practical and real-world problems.

A total of 368 senior high school students were surveyed using the chemical growth mindset scale, academic anxiety scale, and learning motivation scale. The results showed that: (1) The chemical growth mindset of high school students could significantly and positively predict academic performance; (2) Academic anxiety and learning motivation play a partial mediating role in the relationship between chemical growth mindset and academic performance of high school students, and the chemical growth mindset of high school students can further affect academic performance through the mediating effect of academic anxiety or learning motivation, respectively; (3) Academic anxiety and learning motivation are parallel mediating variables for high school students' growth mindset in chemistry to predict academic performance, and the difference in parallel mediating effects is not significant. The results of this study further explain the internal mechanism of chemical growth mindset and academic performance, and provide an empirical basis for improving students' academic performance from the perspective of chemical growth mindset in the future.

Aiming at the problems of traditional self-made water purifiers in junior high school chemistry teaching, such as slow filtration speed, difficult recovery of filter materials, and poor teaching adaptability, this paper proposes a modular simple water purifier scheme. With a multi-layer milk powder box as the main body of the water purification box, combined with a gas-liquid dual-purpose pump and a 180°symmetric eccentric-hole rubber gasket, a layered detachable system is constructed by encapsulating pebbles, quartz sand, activated carbon, and medical absorbent cotton with a sink filter screen. The cost is controlled within 20 yuan. Experimental results show that: the average water production rate of the modular water purifier is 285.77 mL/min, which is 12.5 times higher than that of the traditional device (22.87 mL/min), and it can complete the filtration of 200 mL of sewage in 40 seconds; the turbidity removal rate reaches 98.0% (reducing from 91.1 NTU to 1.8 NTU), it can remove odors, and the pH is maintained at 6.7. The filter material recovery rate of the device exceeds 90%, and it has a compact size (with a diameter of 7.3 cm and a height of 20 cm), which is suitable for classroom and home practice. It can help students understand the logic of “coarse filtration-fine filtration-adsorption” and cultivate their abilities in scientific inquiry and engineering practice.

In the “displacement reactions among halogen elements” experiment from the People's Education Press senior high school chemistry textbook, chlorine water is reacted with potassium iodide and potassium bromide solutions. However, hypochlorous acid in the chlorine water can also oxidize bromide ions and iodide ions, which seriously interferes with students' accurate judgment of the oxidation order of halogen elements. This study intends to adopt a water-free reaction system to eliminate the interference of hypochlorous acid in chlorine water and conduct experimental explorations on other influencing factors. The research results show that the water-free reaction system can effectively avoid the interference of hypochlorous acid, and adjusting the order of reagent addition can make the experiment more convenient and the phenomenon more obvious. This achievement provides a better experimental scheme for senior high school chemistry teaching and also makes up for the deficiencies in the experimental design in the textbook.

In response to the difficulty of understanding the microscopic,abstract,and invisible movement of ions in electrolytic cells,calcein was selected as a fluorescent tracer,U-shaped tubes and test tubes were used as electrolysis devices,and copper and iron plates were used as electrode materials to explore the real-time movement path of ions in different electrolyte solutions without binding the free diffusion of ions. The experiment dynamically presented the ion movement process through fluorescence changes,clarifying that the electric field effect was the main reason for the directional movement of ions between the two poles,and exploring the influence of electrolysis devices and electrolyte solution types on the micro mass transfer process of electrolysis cells. Intended to help students establish a logical connection between electric field action and ion directional movement,develop their core competencies of “evidence reasoning and model cognition”,and enhance teaching effectiveness.

Titration analysis is a crucial component of senior high school chemistry and a fundamental experimental skill that students must master. The 2018 National paper II, 2024 Chongqing paper, and 2024 Anhui examination paper all employed Fe³⁺ titration scenarios to assess students' comprehension of titration analysis. Based on these exam questions, this paper delves into the subject understanding of titration analysis, primary standards, and standard solution preparation, offering insights for teaching and exam preparation in titration analysis.

Does the chemical principle of tofu production using magnesium chloride as a coagulant belong to “protein salting-out” or “colloidal coagulation”? To clarify this conceptual confusion, this article systematically analyzes the essential differences between the two based on colloidal and protein chemistry theories, combined with experimental evidence. Soybean milk is a typical colloidal system; from four core dimensions: mechanism of action, reversibility of the process, dependence on electrolyte concentration and valence, and product structure, it is demonstrated that the essence of tofu production using MgCl₂ as a coagulant is colloidal coagulation: Mg²⁺ compresses the double layer of soy protein colloidal particles in soybean milk, reducing the ζ potential of the colloidal particles to below 20 mV, triggering irreversible aggregation of the colloidal particles and forming a three-dimensional gel network, rather than protein salting-out.