This paper analyzed the characteristics of the theoretical questions in the final of the 2008-2017 National Chemistry Olympiad, such as the distribution of knowledge points, the level of knowledge, chemical thoughts, chemical abilities, and chemical methods. Meanwhile, the beneficial enlightenment on chemistry teaching and contest instruction have been obtained, such as stress the comprehensiveness of chemistry based on problem-oriented, infiltrate of chemical thought by creating problem situation, develop transfer and innovation ability, and emphasize the generation of knowledge structure and scientific methods.

Based on the chemistry core literacy, this paper analyzed the students' knowledge level, ability level and literacy level examined in Chemistry Olympiad Preliminary in recent five years, and put forward suggestions for the teaching practice of cultivating high school students' core literacy.

Silicon, the emiconductor material, is in the third cycle, IVA family. There are four electrons outside the nucleus, with a more stable structure. A brief history of silicon development and application was specified. From the chemical point of view, the elemental structure, preparation technology, reaction mechanism and application mechanism of several typical materials such as silicon, silicon dioxide and organic silicon are analyzed in detail. The future development of silicon is summarized and prospected.

Filter is the core component of air purifier, and its performance and quality have a direct impact on purification efficiency. This paper introduced the air purifier filter from the aspects of species and filtration principle, designed the experimental study on the chemical properties of different filter materials, and compared the filtering effect of different filters. The results showed that PET fiber membrane and PP fiber membrane were resistant to acid and alkali conditions, with poor hygroscopicity and flammability. Compared with coarse filter and activated carbon filter, HEPA filter had better purification effect.

Biomass resources are abundant in nature, but the utilization rate is low, in order to make waste profitable, this paper introduces the method of hydrothermal carbonization of biomass resources to prepare hydrothermal carbon. The hydrothermal carbon has a better specific surface area, higher porosity and better adsorption capacity, and it can be widely used in the adsorption of heavy metal ions, atmospheric pollutants and so on. 4 chemical modification methods of hydrothermal carbon are summarized and discussed, which can improve the adsorption capacity of heavy metals.

This paper analyzes the literature on the chemical "solution" in the ninth grade, and puts forward the teaching of sodium hydroxide as the main line, and conducts a holistic connection between knowledge, guiding students to in-depth thinking, and improving the integration ability of multidisciplinary knowledge. The construction of multi-channel information into the original cognitive system has enriched the cognitive perspective, developed the cognitive mode of student system and change, and presented a teaching design that can be used as a reference.

This paper tested senior high school students' understanding level of concept group about amount of substance by compiling reliable and valid measurement tools, and found that most students were at the level of partial understanding and that of partial understanding with some misunderstanding, there were 14 misconceptions in students' mind on concept group about amount of substance.

In order to deepen students' understanding of the rules of configuration of atomic extra-nuclear electron and to help them to master the writing of configuration of atomic extra-nuclear electron quickly, two teaching models are designed, which are step model and step plus house model, respectively. These two models are introduced to the students. Then their progress resulting from the models is valued by both test questions and interviews and the result is satisfactory. These two teaching models can be referred to and used by middle school chemistry teachers in teaching.

Evidence-based reasoning is to infer new knowledge and principles on the basis of mastering evidence. Evidence-based reasoning is of great significance to scientific development, students' learning and development. In teaching, we should cultivate students' thinking mode based on evidence-based reasoning from the following aspects:awakening the evidence-based instinct and developing the consciousness of collecting evidence; learning the skills of scientific reasoning and making reasonable reasoning spontaneously; sharing the results of evidence-based reasoning and experiencing the joy of evidence-based reasoning.

This paper statistics and analyses the distribution of the chemical subjects in the national youth science and technology innovation competition in the nearly eleven sessions (2007-2017) and the first prize winners in the second-level chemistry disciplines. The results show that the number and quality of award-winning projects in materials chemistry specialty are increasing; organic chemistry and physical chemistry are also hot topics for high school students to explore, the number of award-winning projects is second. Based on the data analysis, this paper summarizes the research fields in which the subjects selected by the high school students are more concentrated, and puts forward some suggestions on the ideas and methods for teachers to guide students to carry out research-based learning.

Based on the outstanding problems in the current chemical equilibrium teaching, a software tool for chemical equilibrium knowledge learning and exercise test was developed with synthetic ammonia as an example. The software adopted the visual technique to display the dynamic process of equilibrium by using histogram, curve and data, and it was convenient for students to obtain information from the reacting images and data, and to carry out reasoning, so as to recognize the principle of chemical equilibrium. This software could not only be used in the teaching of chemical equilibrium concepts, but also for the creation of the necessary teaching situation for the explanation of the chemistry equilibrium exercise class.

The high school textbook Chemistry 2 of People's Education Press clearly points out that benzene can't make acid potassium permanganate solution fade, but we find that it can fade if the mixture of benzene and acidic potassium permanganate solution is placed for some times. This paper accorded the dark or light, adding acid or without acid conditions to do UV-Vis test and took out the precipitate to carry out a XRD test, through the comprehensive analysis of the experimental data, this paper made the appropriate mechanism.

H₂ gas was observed to emit continuously from the NaHCO₃ solution and Mg, H₂ also released continuously from saturated Na₂CO₃ solution and Mg. Therefore, this paper analyzed the thermodynamic data and the kinetic mechanism of the reaction of Mg and H₂O, the results showed that H₂ gas could continuously produce from the reaction of Mg and H₂O by adding some organic ligands (such as glycine ion, oxalate ion, EDTA and etc) or chemicals (such as alkaline salt solution) which could destroy the protective layer of magnesium hydroxide.

On March 31, 2017, the Ministry of Education, Culture, Sports,Science and Technology(MEXT) of Japan issued new Junior High School's Learning Guidelines for Science, which included chemistry curriculum standards. This paper analyzed the background and motivation of the revision, the basic principle of the revision, and key revisions of "Junior High School Chemistry Curriculum Standards" comprehensively and deeply, found that new "Junior High School Chemistry Curriculum Standards of Japan" focused on the clarification of the goals of the curriculum, the systematization of the curriculum structure, the structuring of the content and the concreteness of the instructional guidance.