Chemistry is a natural science and a compulsory course in middle school. It is the result of scientific research and practice of countless Chinese and foreign chemists throughout the ages. It compiles some basic chemical concepts, basic theories, knowledge of elemental compounds, basic types of chemical reactions, classification of inorganic substances and their relationships. It is full of the principles and contents of materialist dialectics, and introduces the excellent qualities of many scientists, the scientific attitude of seeking truth from facts and the rigorous style of study. Chemistry plays an important role in industrial and agricultural production, national defense and modernization of science and technology, and people can't live without chemistry.
2. Preview before class
The day before class, you must take time to preview what the teacher will say the next day. Learning to preview before attending classes is a good learning method. Preview has many advantages: (1) it can strengthen the pertinence of lectures, help to find problems, grasp key points and difficulties, and improve the efficiency of lectures; (2) It can improve the level of taking class notes, knowing what to remember, what not to remember, what to remember in detail and what to remember slightly; (3) It can save time for reviewing and doing homework after class. Shorten the time of reviewing and doing homework after class through independent thinking in preview and deep impression left in class; (4) Self-study ability can be cultivated. The process of preview is a process of conscious or independent thinking. If you persist for a long time, your self-study ability will improve.
The method of preview is: (1) Read through the text. By reading the text, you can understand the basic content and key points of the new lesson. You should write down the questions you don't understand or make some marks on the book with a pencil to remind yourself to pay attention in class, listen to the teacher's questions you don't understand consciously and purposefully, and compare them with your own ideas in detail, so as to achieve good learning results. (2) Remove obstacles. On the basis of reading the text and understanding the main content, contact the basic knowledge related to it that has been learned. If there is any forgotten place, review it in time to make up for it, so as to connect the old and new knowledge and bring the new with the old to review the old and learn the new; (3) Determine the key points, difficulties and doubts. After reading through the text and clearing the relevant obstacles, on the basis of understanding the new knowledge, think about the exercises after the text, try to answer them, and find out the key points, difficulties and doubts of the new lesson in the process. If you have the potential, you can also take some preview notes.
3. Listen to every class.
Listening to lectures is the core link in the learning process and the main way to learn and master knowledge. Whether you can master what you have learned in class is the key to determine the learning effect. The merit lies in the classroom and the benefit lies in the classroom. If you can basically master the basic knowledge and skills learned in class, there will be no difficulty in reviewing and doing homework after class. If you don't pay attention in class and don't understand in class, problems that can be solved in a few minutes may take several times to make up after class. Therefore, it is the key to let students concentrate on listening to each lesson in class. When listening to the class, you must concentrate on it, not only listen carefully to the teacher's explanation, but also pay special attention to the ideas that the teacher has said and the key points and difficulties that have been repeatedly emphasized. While listening to the class, take notes, mark or write down what you don't understand, and ask the teacher or classmates in time after class. At the same time, we should also pay attention to students' answers to teachers' questions and teachers' evaluation of students' answers: which are correct, which are incomplete and inaccurate, and point out mistakes, so as to deepen our understanding of knowledge and judge right and wrong. Classroom teaching is a two-way activity of teaching and learning. Students are the main body and teachers play a leading role. Students should actively participate in classroom teaching. In class, we must eliminate all distractions and distractions, keep our eyes on the teacher, follow the teacher's lectures and demonstrations, think positively, observe carefully, speak enthusiastically, remember in time, seize the time given by the teacher in class, do a good job in class exercises and try to digest what we have learned in class.
4. Take notes carefully
Taking notes is also an important part of learning chemistry well. Taking notes can not only concentrate and improve the efficiency of class, but also help you review after class. So learn to take notes and form a good habit of taking notes. Therefore, while listening carefully, we should also take notes. The types of notes are:
(1) Supplementary explanation. Make supplementary notes in the new class. The teacher's content is to reorganize the teaching material content according to the students' reality and highlight the key points. Taking notes means listening to the lecture while reading, marking the key points in the book, copying down the outline and key points written by the teacher on the blackboard while speaking, writing a few words on the key points, laws, substantive contents and places that briefly inspire you in the book or notebook, and writing down the teacher's notes.
(2) experimental notes. Teachers' demonstration experiments and students' grouping experiments focus on verifying chemical principles or mastering chemical properties or preparation methods of substances through experiments. You can make concise illustrations and supplementary explanations, and record the phenomena and explanations of the demonstration experiment made by the teacher. If there are experimental illustrations in the book, you can supplement them directly. For example, write the teacher's key points on the side of the schematic diagram of the oxygen laboratory preparation device: ① Drugs should not be piled at the bottom of the test tube, but should be laid flat on the bottom of the test tube, remember: "It is to increase the heating area, so that the drugs can be heated evenly and the gas can easily escape"; ② When heating the test tube, why do you reheat the alcohol lamp after coming down from the test tube, and then focus on the medicine? Note: "Let the test tube be heated evenly and not easily broken".
(3) Correct the wrong notes. Exercise or examination paper evaluation is a classroom where teachers correct the "conventional weapons" in students' homework or examination papers and guide the thinking, rules, skills and methods of solving problems. Don't just copy the correct answers in class. The key is to correct with a red pen, and don't erase your own wrong solution, so as to compare with the correct answer and find out the reason for the wrong answer. Do the wrong question again after a while to see if it is really there now. This kind of note is a concise "eyebrow criticism" or "annotation" between assignments or test questions.
(4) system comments. When reviewing the summary lesson, the teacher systematically summarized the contents of the textbook, which is not in the book, so he should take systematic notes. Divide each side of the note into two parts, half of which are written on the blackboard and the other half are explained. After class, we should organize, modify and supplement the review to make it a whole, so as to deepen and consolidate the knowledge we have learned and improve the ability of knowledge summary and comprehensive review. The forms of notes are: ① outline, mainly written, suitable for summarizing the main contents of textbooks or summarizing formulas, theorems and concept points; (2) Outline formula, expressed by chemical formula, relational formula or relational block diagram, is suitable for summarizing the properties, preparation, mutual changes and calculation knowledge of elements and their compounds. ; (3) Chart type, represented by words, tables and line charts, is suitable for classifying and comparing related concepts, basic principles of chemistry, material properties and experiments.
5. Careful observation and hands-on experiments
Chemistry textbooks for compulsory education have compiled 8 1 demonstration experiments,1compulsory student experiments and 9 selected experiments, and arranged 13 small family experiments. Therefore, through these demonstrations and students' experiments, learning to observe the operation and phenomena of teachers' demonstration experiments, learning to do students' experiments independently and having a good experiment class are the basis for learning chemistry well.
First of all, we should carefully observe the operation and experimental phenomena of every demonstration experiment done by the teacher in class. Chemistry experiment is very vivid and intuitive, and the ever-changing phenomena in the experiment can stimulate students' interest best. However, if students only watch the excitement and don't think about the phenomenon, they won't know what is going on after reading it, which will not help improve their study. Therefore, observation should have a clear purpose. What should be observed clearly before observing the experiment? What is the scope? Solve what problem? This is the purpose of so-called clear observation. Only with a clear purpose can we grasp the key points of observation and observe. Careful and comprehensive observation. For example, the demonstration experiment of hydrogen reduction of copper oxide aims to verify the redox reaction, and copper oxide is reduced to copper by hydrogen. When observing, it is clear that the reactants are colorless hydrogen and black copper oxide powder, the reaction conditions are heating, and the products are water and bright red copper.
Secondly, in order to give students a good experimental class, we must preview before class and make clear the purpose, principle and operation steps of the experiment. When conducting an experiment, do it yourself, don't be a bystander, carefully do every experiment arranged in the experimental content, pay attention to it during the experiment, operate in strict accordance with the experimental requirements, practice the basic operation repeatedly, patiently and carefully observe various phenomena during the experiment, think carefully, and record accurately and truly.
6. Review in time after class
The content of a class can be reviewed in more than ten minutes, and sometimes it can be repeated like a movie. Review can deepen understanding and consolidate knowledge.
The review should be timely, not delayed. Ask the teacher if you have any questions you don't understand in the review, so that you won't leave obstacles and doubts in your study. When reviewing, you should pay attention to the textbook, read the handout, read it repeatedly, remember the teacher's explanation while reading, and understand the contents of the book.
7. Finish your homework carefully
Doing homework is an excellent opportunity for practice and one of the important means to consolidate knowledge. Students must do it by themselves and never copy other people's homework. The exercises after the festival and the review questions after the chapter must be carefully completed and not sloppy. Do your homework after review, in order to get twice the result with half the effort. We must actively and independently complete each assignment, think more and ask more questions, and keep all the assignments in mind as much as possible, because without memory, there is no solid knowledge. Only by careful memory can practice make perfect, and we can be "smart" on the basis of diligent practice.