1. Reflections on the teaching of chemical solutions in the first volume of Grade Three.
I think the success of this course design lies in that both teaching design and teaching are carried out under the guiding ideology of "student development-oriented". The whole class strives to take students as the main body and fully mobilize their enthusiasm and initiative. According to the content of the textbook, set up a certain scene of life problems, stimulate students' strong thirst for knowledge, and mobilize students' initiative and enthusiasm for inquiry. It embodies the concept of "let students feel chemistry in familiar life scenes". By connecting with common phenomena in life, students can feel that chemistry is around and realize the important role of chemical knowledge in solving practical problems in life and society, thus stimulating students' thirst for knowledge and interest in learning. The teaching structure is "question-experimental inquiry-conclusion-application", which guides students to carry out experimental inquiry in actual problem situations. In teaching, group independent cooperation and inquiry is the main activity line, so that students can experience the generation and formation of knowledge through observation, discussion and communication, and students' participation consciousness, cooperation spirit, experimental operation and inquiry ability can be fully brought into play. The level of knowledge understanding and cognition, the ability to analyze and solve problems are improved in the inquiry. This design not only achieves the goal of knowledge and skills, but also embodies the process and method, emotional attitude and values.
In the teaching process, we should properly use modern educational technology to guide teaching, use multimedia to make students feel the microscopic process of material dissolution vividly and intuitively, guide students to understand the dissolution process from the microscopic point of view, and help students complete the transformation from macro to micro and from sensibility to rationality, so as to break through the teaching difficulties. Animation shows the microscopic process of detergent decontamination principle to help students understand the essence of emulsifying phenomenon.
Of course, through the practice of classroom teaching, I found that there are still some shortcomings, such as: the design ideas are not open enough; Classroom teaching adopts the learning mode of students' autonomy, cooperation and inquiry, which puts high demands on teachers' organizational ability and tact.
2. Reflections on the teaching of chemical solutions in the second volume of Grade Three.
This week, we finished the last unit "Solution" before the exam, and learned "Formation of Solution", "Solubility" and "Concentration of Solution". In the teaching process, it is found that it is easier for students to understand and accept knowledge by experiments. For abstract or large amount of calculation, the reception is slow. In view of different problems in teaching, we adopt different methods to solve them. For example, "concentration of solution" is to further understand the solution from the perspective of quantity, and to further learn the methods of quantitative research of substances and relatively simple chemical calculations. Learning "percentage" and "percentage" in math class is helpful for students to understand quality scores. In teaching, I found that students' understanding of the meaning of solute mass fraction is incorrect, and they can't analyze the specific situation of substance dissolving in water and make mistakes. Therefore, I attach importance to concepts and students' thinking process of analyzing problems in teaching. When studying the mass fraction of solute, I especially emphasize that the part of solute that is not completely dissolved can not be included in the mass of solution and solute, and also emphasize that chemical calculation can not be divorced from reality, otherwise it is meaningless. When solutions with different densities (different mass fractions) are mixed, a large number of students think that the volumes add up. I use examples to illustrate this point and strengthen guidance. Students have understood that the volumes of solutions with different densities cannot be simply added up. The quality and volume of the solution should be converted by density, and the volume of the solution should be converted into the quality of the solution, and then the questions should be answered as required. Students should also be reminded not to confuse the density of solution with the density of pure solute. The quality of solution is obtained from the density of solution, not the quality of solute.
Secondly, by enumerating examples in life, students can overcome unacceptable abstract knowledge and further build a knowledge network. Contact existing knowledge. If the calculated value is large, explain it through specific examples, lead students to see the calculation steps and methods step by step, and help them simplify the operation and get the numerical value accurately.
3. Reflections on the teaching of chemical solution in the second volume of Grade Three.
Is this lesson quoted by the historical story Zheng He's voyage to the West? Sea? There are many substances dissolved in it. What is this? A mixture. Sea? what's up A solution. Through the experiment of sucrose dissolution? Learn step by step? Observe the whole process of solution formation. The onlookers principle of the phenomenon analysis solution: sucrose table? Integral? Are you online? Integral? Work? Next, gradually spread to the last sucrose? Both? Scattered to? Integral? In the middle, molding? A mixture-sucrose solution. A compliment? Third, let the school? From macro and micro? Degree analysis? Dissolution of salt. Solution is a common substance, but what about learning? what's up Life is closely related, so study? Familiar substances, through the analysis and induction of familiar substances, will learn? The perceptual knowledge of solution rises to rational knowledge. Microscopic understanding of dissolution process? More abstract,? Multimedia-assisted instruction helps learning? Understanding is more intuitive. Are you online? Should the discussion of life solutions be taught? Fully understand the solution in? Production? Work in life? Recognizing the social significance of chemistry is enlightening for learning? Interest in learning. Emulsion and emulsifying phenomenon Textbooks? Simple, so histology? By reading textbooks? Learning, cultivating learning? what's up Learn energy? . A lot of content in the textbook is learning? In the inquiry activity, so that you can? Encourage learning? Participate? Encourage learning? Communication fosters learning? Ability to observe, record and analyze experimental phenomena? .
But learn? Sometimes there will be mistakes in the judgment of solvents, so we should strengthen our practice. Master the content of this lesson.
4. Reflections on the teaching of chemical solution in the fourth volume of Grade Three.
According to your previous teaching experience, do you know how to learn? Learn this? In the chapter, the more you get to the back, the more you will cross the lake, so you are willing to pause and slow down first? Next, help with your study? Clear your mind for the future? Lay a solid foundation for calculation, and practice has proved that grinding? Don't miss chopping wood, it works well. Mainly reflected in two places? . ? It's difference and connection. Want to learn? Study hard and remember well, okay? Is there a law between knowledge points? Network, knowing the same but different. Are these two questions being solved? It can be described as incisive. With the concept of solution, the conditions will be narrowed and the temperature will be specified. Not at any time; With saturated and unsaturated, for? More capable? Yes? Added it again? A standard? Everyone is dissolved at100g, so there is the concept of solubility, which is a progressive relationship. In order to make the expression more vivid, I also? Graphics to illustrate,? The circle is a solution, which is divided into two parts, saturated solution and unsaturated solution. ? In saturated solution? Painting? Answer? Tu Tu is solubility. Come down like this, have you learned? Basic understanding, practice and consolidation.
First one? A piece of land? Is the relationship between saturation and concentration. Me? Can you be more detailed after learning? What does an alien eat? , is often calculated by "barrels", eat more, is "thick", but if only give it to him? The bucket is also "thick", but it is not full, that is, "unsaturated solution"; Study? I'm beginning to understand. And then what about me? Ask your classmates how much you eat. Just two bowls, full of saturated solution, but? The "bucket" just now is a dilute solution. Practice and learn? For this? The problem can basically be solved? Solution.
5. Reflections on the teaching of chemical solution in the fifth volume of Grade Three.
The determination of solute and solvent in chemical solution is too simple and tasteless from the knowledge in the book. Some students think it is not appropriate to understand the calculation of solute mass fraction and find out what solute is. What is the mass of the solvent? So this year I tried to practice after talking about the composition of the solution: put iron in dilute sulfuric acid solution. At first, some students thought that the solute was iron and the solvent was dilute sulfuric acid, but after discussion and analysis, 90% of the students understood how to determine the solute and solvent when some substances were put into another substance. Some substances will change chemically when put into another substance, so how to determine the solute and solvent? Then practice how to determine the solute and solvent when limestone is put into dilute hydrochloric acid solution. How about further analysis and comparison of solvent quantity? Because the teaching of solution is based on students' reality, the teaching task in this section has been completed well, which has laid a solid foundation for the teaching of solute mass fraction in the future.