Every teacher wants their subject to arouse deep interest among students, so that students can not only write chemical formulas and reaction equations, but also understand the chemical picture of the world and be able to think logically, so that in every lesson they understand chemical processes and acquire solid knowledge.

To do this, you need to make the student an active participant in the educational process. A student can learn information only if he/she is interested in the subject and involved in the lesson process. Therefore, the teacher needs to become a facilitator, not an informer. It gives pleasure to the student when he independently achieves the goals of the lesson and feels his capabilities. The student asserts himself as an individual.

In order to improve the quality of the lesson and involve students in the lesson process, after studying the literature, I chose the problem-based learning method. Problem-based learning is an approach that allows students to actively engage in the learning process, analyze phenomena, look for solutions to problems and apply acquired knowledge in practice. This method is especially effective for developing analytical skills in describing chemical processes, since it requires students not only to know the theory, but also to be able to interpret data, identify patterns and draw reasonable conclusions.

Problem-based learning as a pedagogical approach has developed through the research and ideas of many scientists, educators and psychologists. M.I. Makhmutov believes that problem-based learning is a type of developmental education that combines systematic independent search activity of students with their assimilation of ready-made scientific conclusions. The system of methods is built taking into account goal setting and the principle of problematic nature. Moreover, the process of interaction between teaching and learning is focused on the formation of students’ cognitive independence, stable learning and mental motives, including creative abilities in the course of their assimilation of scientific concepts and methods of activity, determined by a system of problem situations [1].

John Dewey is an American philosopher, educator and psychologist who is considered one of the founders of the ideological approach to problem-based learning. In his work “As We Think” (1910), he emphasizes the importance of active participation of students in the educational process through solving real problems. Dewey believed that learning should be based on the experience of students, and the process of cognition should be associated with practical activities because students learn better when they are exposed to real-life challenges. Thus, training should be interactive and problem-solving.

Piaget emphasized the importance of independent exploration and activation of thinking for learning. His theory of the stages of cognitive development became the basis for understanding how children solve problems at different stages of adulthood. Children acquire knowledge through interaction with the environment. Problem solving stimulates the development of cognitive skills.

Lev Vygotsky emphasized the role of interaction between students and teacher in the learning process. His concept of the “zone of proximal development” is key to problem-based learning.  The tasks should be slightly above the students' current level of knowledge to stimulate their development. The teacher or a more experienced student plays the role of a “guide” in solving complex problems.

Problem-based learning in chemistry promotes the development of analytical skills, as it requires students not just to memorize information, but to actively search for solutions, establish cause-and-effect relationships, and critically analyze data. Analytical thinking is the ability to study and evaluate information, identify patterns and relationships, and draw logical conclusions. It involves breaking complex problems into smaller, more manageable parts and using evidence and reasoning to solve them.

The purpose of the study is to develop and test a methodology for developing analytical skills in students when studying chemical processes through problem-based learning. The following methods were used as part of the study: analysis of pedagogical, methodological and scientific literature on problem-based learning and chemical education. The study involved 44 9th-grade students (14-15 years old). Experimental and control groups were selected. A survey was conducted among students about difficulties in studying chemistry and chemical processes. The 5W method helps students analyze the material they are studying in greater depth by asking key questions about each topic. The Fishbone method is excellent for analyzing cause-and-effect relationships. The 5E elements technique make chemistry lessons interactive and interesting. Creating maps and diagrams helps visualize information and structure it, making it easier to remember. This facilitates the learning process and develops the ability to systematize knowledge. The use of such methods makes chemistry lessons more productive, interesting and focused on the development of analytical thinking. They allow students not only to memorize information, but to understand it more deeply, see connections between different phenomena and apply knowledge in practice. The study showed that in the second quarters, the quality of students' knowledge improved significantly due to the use of modern methods than in first quarter. Analysis of the results revealed that the use of above-mentioned methods made it possible to increase the level of understanding of chemical processes and increase the percentage of successful answers on tests. An increase in student motivation and their involvement in the learning process was also noted. To assess the effectiveness of the implemented methodology, a comparative analysis of the level of analytical skills of students in the control and experimental groups was carried out. In the experimental group, where modern teaching methods were used, there was a significant improvement in performance. The average test score for analyzing and solving problems in the control group was 65%, while in the experimental group it was 82%. To statistically assess the significance of differences between groups, Student's t-test was used. The results obtained showed that the difference between the average values is statistically significant (p < 0.05), which confirms the effectiveness of using innovative methods in teaching. Correlation coefficient between the level of analytical thinking and success of execution control tasks was 0.78, which indicates a strong relationship between these parameters.

The use of such methods makes chemistry lessons more productive, interesting and focused on the development of analytical thinking. They allow students not only to memorize information, but to understand it more deeply, see connections between different phenomena and apply knowledge in practice. The research results confirm that the application of problem-based learning and modern methods such as 5W, Fishbone, 5E, and mind maps significantly improves students' analytical skills. The effectiveness of the implemented methodologies has been demonstrated in terms of knowledge quality improvement, increased engagement levels, and students' ability to apply acquired knowledge in practice. Statistical data analysis revealed a significant difference between the control and experimental groups, indicating the feasibility of widespread adoption of these approaches in chemistry education. The development of analytical thinking not only enhances subject comprehension but also fosters skills essential for students' future professional activities.

1. Makhmutov M.I. Problem learning. Basic questions theory. - M.: Pedagogika, 1975. - 365 p. 2. Dewey J. Psychology and pedagogy of thinking / Transl. From English N.M. Nikolsky; Ed. N.V. Vinogradova.-Moscow: Mir, 1919-112 pp., 3. Sitarov V.A. Problem-based learning as one of the directions of modern learning technologies // Znanie. Understanding. Skill. - 2009. - No. 1. - S. 148-157. 4. Karaseva E.M. Problem-based learning as a means of forming students' ability to act independently // Contemporary pedagogy. 2014.-#5. 5. Organization of problem education in school [Text] / M.I. Makhmutov. - Moscow: Prosveshchenie, 1977. - 240 p. 6. Technologies of problem-based learning [Electronic resource] / File archive of students / Access mode: https://studfiles.net/preview/3299303/ - article on the Internet (date of circulation: 02.10.2018). 7. Brushlinsky A.V. Psychology of thinking and problem-based learning.-M. “Knowledge”, 1983-96 pp.,