Lemons and limes are widely loved for their unique flavor and have been deeply integrated into people’s daily lives. However, the appearance and flavor of lemons and limes are very different. This paper elaborates on the chemical composition, nutrient composition and flavor differences of lemons and limes, and provides authentic contextual materials for teaching organic chemistry in secondary schools.

Artificial intelligence is profoundly reshaping the landscape of basic chemistry education. Knowledge acquisition has become unprecedentedly efficient, yet “learning how to learn” has emerged as a prerequisite; the hands-on experience and scientific inquiry inherent in laboratory teaching remain irreplaceable. At a deeper level, student assessment and teacher evaluation systems are in urgent need of transformation that is from knowledge recall to competence and literacy, while school management and textbook development also face systemic restructuring. In response to the insufficiently addressed challenges of lagging pre-service teacher preparation and the persistent difficulties faced by in-service teachers in continuing professional development, this paper proposes reforming teacher-training curricula, establishing support systems for teacher development, and systematically reforming evaluation mechanisms, with an emphasis on safeguarding the essential mission of education amid technological empowerment.

To address the problem of fragmented knowledge in junior high school chemistry review classes, this study takes the “I am a fire extinguisher designer” project as the carrier, integrating the thematic review of carbon dioxide into a progressive engineering design process. Centered on the “thinking model for understanding chemical changes” as the core thread, the study designs sequential inquiry tasks to guide students in completing the transformation from chemical principles to technical products, thereby achieving the synergistic development of knowledge structuring, model-based cognition, and engineering thinking.

Based on the integration of teaching, learning and assessment, the topic of “molecules and atoms”is designed and implemented as a whole. Starting from the epistemological function of molecules and atoms, authentic cognitive contexts are transformed into learning tasks. Through performance activities such as explanation, drawing, model making, and model disassembly, students’ misconceptions are externalized. Interactive approaches including peer communication, group assessment, student questioning, and teacher questioning are employed to help students build a “bridge”from macroscopic to microscopic understanding through evaluative feedback, guiding the formation of a cognitive pathway from the macro to the micro level and promoting the development of microscopic understanding.

This study takes the structure and properties of the “amide” group as the knowledge foundation and “designing a science popularization card for silk care” as the core project theme,establishing a teaching framework characterized by “overarching project guidance — progressive sub — projects”. Through three scaffolded tasks: “investigating common detergents and their cleaning principles” “exploring the relationship between silk composition and detergent alkalinity/acidity” and “examining the relationship between silk composition and washing water temperature”,students are guided from real-life situations to systematically integrate knowledge modules such as carboxylic acid derivatives and protein structure,employing methods like experimental inquiry,analogical reasoning,and model construction. The research finds that project-based learning effectively enhanced students’ deep understanding of the “structure-property-application” cognitive model,enabling them to grasp the scientific approach of analogical thinking by comparing the hydrolysis characteristics of ester and amide groups. Furthermore,it strengthened their ability in evidence-based reasoning through experimental design and phenomenon analysis,while fostering interdisciplinary practical skills and social responsibility through iterative refinement of the science popularization cards. Practice demonstrates that project-based teaching grounded in authentic problems can achieve knowledge structuring,visualization of thinking,and explicit manifestation of competencies,providing a referable paradigm for in-depth teaching of organic chemistry.

Facing the common issues of “knowledge listing and mechanical memorization” in the “matter structure and properties” module of senior three review classes, this lesson proposes the teaching idea of “thinking like a scientist”. Using the cutting-edge achievement of Chinese scientists successfully preparing calcium bicarbonate crystals as the exploration carrier, students are guided to simulate the analysis and solution process of scientists, and deeply understand the inherent logic among “macroscopic properties-microscopic structure-interactions between particles”. The teaching goes through five progressive stages: “discovering anomalies→attributing structure→analyzing effects→proposing solutions→verifying and characterizing”, allowing students to experience the complete thinking process from abnormal properties to structural interpretation, and then to condition regulation. This internalizes the core concept of “structure determines properties” as a transferable analytical tool, effectively developing students’ core competencies such as “macroscopic identification and microscopic exploration” and “evidential reasoning and model cognition”.

To address the problems of fragmented model transfer, difficulties in knowledge transfer to unfamiliar situations, and superficial application of artificial intelligence (AI) in the first-round review of galvanic cells for senior three chemistry, this study took “chemical energy and electric energy” as the theme and carried out inquiry-based teaching with the core task of “designing new chemical power sources”. By constructing a teaching model of “model deconstruction and reconstruction—transfer and revision—application and reflection”, the generative AI system was positioned as a “visualization assistant”, “engineering consultant” and “socratic tutor”, running through the complete learning process of “model establishment→scheme design→AI evaluation→revision and optimization→reflection and transfer”. Teaching practice shows that this model can effectively guide students to construct a systematic cognitive model of “electrode reaction—electrode material—ionic conductor—electronic conductor”, break through the mindset of aqueous solution systems, improve students’ ability to analyze, design and evaluate batteries in real and complex situations, and promote the formation of “human-machine collaboration, people-oriented” AI literacy. This study provides an operable and replicable implementation path for developing students’ model cognition and higher-order thinking, and promoting the intelligent transformation of chemistry review teaching.

To elucidate the cognitive processing disparities between students of varying academic performance levels when solving redox reaction problems, this study employed event-related potential techniques to record electroencephalographic data from 30 first-year senior high school students (15 high-achieving and 15 low-achieving) as they completed tasks of differing difficulty. The N200, P300, and N400 components, along with behavioral performance, were analyzed. The results revealed that high-achieving students exhibited efficient attentional resource allocation (enhanced P300 amplitude) and fluent semantic integration (positive deflection of N400) on simple problems, while flexibly shifting to deeper semantic processing (enhanced negative N400 amplitude) on more challenging problems. In contrast, low-achieving students displayed cognitive conflict and initiation difficulties even on simple problems (increased N200 amplitude and insufficient N400 activation), and became entrenched in a rigid state characterized by “high conflict, low integration” when faced with difficult problems. These findings indicate that high-achieving students possess the capacity for flexible cognitive resource modulation, whereas low-achieving students exhibit processing rigidity and resource depletion. The study provides electrophysiological evidence to inform differentiated instructional strategies.

High school students commonly experience spatial cognitive barriers when learning about network crystals, and merely observing static physical objects or 3D virtual models is insufficient to break through this bottleneck. To address this issue, this paper utilizes Generative Artificial Intelligence (GenAI) to assist in the development of “scaffolded unit cell models” and constructs three types of teaching scaffolds:“spatial positioning and quantitative analysis” “element deconstruction and viewpoint focusing”, and “structural evolution and knowledge transfer”. By designing structured prompts, abstract teaching intentions are transformed into lightweight interactive functions on the web end. Taking diamond and monocrystalline silicon as examples, this paper analyzes the implementation process of core teaching functions such as fractional coordinate conversion, dynamic tracking of specific six-membered rings, and structural evolution. On this basis, a visual teaching resource library covering more than 20 types of crystals has been established. Teaching practice shows that this model can effectively help students overcome core cognitive difficulties and make accurate judgments even when faced with complex variations.

Focusing on the thematic experiment “Exploring the Differences in Gas Exchange of Green Plant Leaves During Day and Night” from the junior high school chemistry curriculum standards,qualitative and quantitative investigations were conducted. Qualitative investigation could only detect the content of a single gas,failing to simultaneously reflect the coupled changes of two gases or continuously monitor the dynamic gas processes. By employing handheld technology for quantitative monitoring,continuous changes in CO₂ and O₂ under light and dark conditions could be captured in real time. The experiment revealed that under insufficient CO₂ in a closed system,an abnormal phenomenon of simultaneous decline in both O₂ and CO₂ occurred under light,which was rooted in the fact that low CO₂ promoted photorespiration in plants. With appropriate supplementation of CO₂,the normal pattern of CO₂ decrease and O₂ increase under light was restored. This study delved into the abnormal phenomenon,providing a model for objectively viewing experimental anomalies and cultivating scientific inquiry thinking.

To address the drawbacks of traditional gas experimental setups, such as complicated structure, cumbersome operation and inadaptability to group teaching, this study develops an innovative integrated apparatus for gas preparation and property verification. Featuring low cost and wide applicability, it offers a replicable and promotable new model for group gas experiments in high school chemistry.

Taking the question “Why is the reaction between zinc and water difficult to occur” as context, this paper analyzes the reaction between zinc and water from both thermodynamic and kinetic perspectives and conducts experimental investigations. Thermodynamic calculations indicate that zinc can react with water. The innovative experiment utilized chelating agents such as EDTA tetrasodium salt to disrupt the protective film on the zinc surface. By increasing the temperature, constructing a galvanic cell, and enlarging the metal surface area, the hydrogen overpotential was reduced, thereby enabling the visualization of the reaction between zinc and water. This revealed the fact that zinc is capable of reacting with water. The improved experiment presents distinct phenomena, which effectively stimulates students’ enthusiasm for scientific inquiry and fosters the development of their disciplinary core competencies, including macroscopic identification and microscopic analysis, evidence-based reasoning and model cognition, and scientific inquiry and innovative awareness.

Changing the temperature causes multiple equilibria to shift,the attribution problem of the equilibrium conversion rate of raw materials and the equilibrium selectivity of products varying with temperature has developed into a universal confusion problem among teachers and students. This paper examines Question 13 from the 2023 Jiangsu Province National College Entrance Examination (a parallel reaction system) and Question 13 from the 2022 Jiangsu Province National College Entrance Examination (a consecutive reaction system) as case studies. It investigates the influence of temperature on conversion rates and selectivity within multiple equilibrium systems through integrated perspectives, including the unity of opposites,quantitative calculations,and qualitative principles of chemical reactions, and establishes a generalized analytical approach for addressing such phenomena.

Against the backdrop of frequent global scientific issues, chemistry education is facing a triple tension among the systematic nature of knowledge and the complexity of problems, the disciplinary boundaries and the interdisciplinary nature of issues, and value neutrality and the intervention of responsibility. Based on the Stockholm Future Chemistry Declaration and IUPAC’s Guiding Principles of Responsible Chemistry, it is proposed that chemistry education should shift from knowledge transmission to systems thinking, from discipline-centeredness to problem integration, and from ethical neutrality to value intervention as a path of value reconstruction. Furthermore, practical pathways should be built from three aspects: issue-driven curriculum organization, presentation of systems thinking content, and the reciprocal relationship between research and teaching, providing theoretical support and an action framework for cultivating chemistry talents capable of addressing complex global challenges.

In 1898, following the recognition of the noble gases as a new group in the periodic table, William Ramsay, guided by periodic trends within the group, predicted the existence of krypton and, together with Morris Travers, isolated and identified krypton from fractionated liquid air, thereby supporting the rationality of Group 0 in the periodic table and deepening the understanding of the noble gases. In 1920, Francis William Aston discovered six isotopes of krypton, which promoted the transition from viewing krypton as a substance with a single atomic weight to understanding it as an isotopic ensemble, thus laying the foundation for the modern concept of krypton. In 1963, the discovery of krypton difluoride (KrF₂) led to the realization that the “inertness” of krypton is not absolute but strongly dependent on external conditions and reaction pathways, thereby advancing noble-gas chemistry and the understanding of chemical bonding. In summary, the formation and development of the concept of krypton served as a crucial bridge in refining the periodic law and advancing the understanding of atomic structure and chemical bonding theory.