It is the requirement of quality education to apply the function of subject education in chemistry teaching and cultivate students' core literacy, which is of great significance to improve students' comprehensive ability and quality. Paying attention to the differences between chemistry and other disciplines and cultivating students' core literacy can start with standardizing the use of chemical language, establishing basic concepts of chemistry, cultivating chemical learning ability, attaching importance to chemical experimental ability, and cultivating chemical values, so as to guide students to look at the material structure and changes from a microscopic perspective, express them in concrete language, explore knowledge through experiments, and improve students' core literacy in an all-round way.
Key words:
Junior high school chemistry; Core literacy; Teaching strategies;
abstract:
Using the educational function of chemistry teaching to cultivate students' core literacy is the requirement of quality education, which is of great significance to improve students' comprehensive quality. Teachers should pay attention to the differences between chemistry and other disciplines, and adopt corresponding teaching strategies to cultivate students' core literacy: standardizing chemical language, establishing basic concepts, cultivating learning ability, attaching importance to experimental ability and cultivating chemical values. At the same time, teachers should guide students to observe the structure and changes of substances from a microscopic point of view, express them in concrete language, and explore knowledge by experimental methods, so as to comprehensively improve students' chemical core literacy.
Key words:
Junior high school chemistry; Core literacy; Teaching strategies;
Today, with the implementation of quality education, in order to promote the all-round development of students, we should actively change the teaching concept of exam-oriented teaching and pay attention to cultivating students' core literacy. As one of the necessary scientific literacy for students, the core literacy of chemistry is of great significance to their long-term development. Therefore, in junior high school chemistry teaching, teachers should focus on students' future development needs, actively use the educational function of chemistry, and cultivate students' core literacy. Based on the teaching practice of Chapter 7 "Ordinary Alkali" in junior middle school chemistry of Shanghai Education Publishing House, the author makes a deep exploration on how to cultivate students' core literacy.
First, the connotation of chemical core literacy
Literacy is the ability and skill acquired through training and practice, and core literacy is the most important and essential basic literacy that a person should possess. Chemistry core literacy refers to the comprehensive expression of basic knowledge, key abilities and methods, emotional attitudes and values gradually formed in the learning process of chemistry courses. It is a comprehensive quality with discipline characteristics, which is manifested through chemistry learning. Its core literacy connotation includes knowledge, ability and values (see figure 1).
In junior high school, although the' chemistry' knowledge students have learned only accounts for a small part of the total chemistry knowledge, it is a key stage for students to lay the foundation of chemistry knowledge. At this stage, whether students have independent chemistry learning ability and correctly establish emotional attitudes and values about chemistry learning will have an important impact on the cultivation of students' chemistry literacy.
Second, chemistry teaching requirements for core literacy training
The core literacy of chemistry is not only to master some chemical knowledge and ability, but also a comprehensive embodiment of knowledge, ability and values. To cultivate students' core literacy in junior middle school chemistry teaching, we should pay attention to the differences between chemistry and other disciplines and master the unique role of chemistry in cultivating students' core literacy.
First of all, we should look at the material structure and change from a microscopic point of view.
Chemistry studies the structure, properties and changes of matter from the microscopic point of view of atoms and molecules. To learn chemistry well, students should not only know the substance and its changes from a macro perspective, but also learn chemistry from a micro perspective. Because students can't observe the movement and change of material particles, teachers should be good at demonstrating the reaction and change of material particles for students with the help of modern information technology, so that students can establish microscopic concepts and pay attention to understanding the world from a microscopic perspective.
The second is to express it in a specific language.
Chemistry has its specific expression language, and chemical symbols, as international symbols, are not only symbols representing material structure and chemical change process, but also the basis for students to learn chemical knowledge, and each symbol has its specific meaning. Refined chemical language can not only express the composition of matter, but also express the process, phenomenon and result of chemical reaction of matter. Therefore, it is necessary to guide students to master chemistry language skillfully and cultivate their core literacy in chemistry.
The third is to explore knowledge through experiments.
Chemistry is based on experiments, which enables students to deeply understand and master chemical concepts and laws, and students' exploration of chemical knowledge is also inseparable from chemical experiments. Chemical experiment can cultivate students' scientific exploration spirit and innovation ability, which is an important content of chemical core literacy. Therefore, in chemistry teaching, we should not only attach importance to the teaching of basic chemical theory, but also attach importance to the teaching of chemical experiments, so that students can master experimental methods and verify chemical results, which is of great significance to the formation of students' scientific attitudes and values.
Third, based on chemical core literacy training teaching strategies
(A) standardize the use of chemical language
Chemical language is the basic carrier for students to know chemistry and learn chemical knowledge. For junior high school students who are new to chemistry, to learn chemistry knowledge well and lay a good foundation for future study, they must master the correct and standardized chemical language from the beginning, not only to read and write correctly, but also to use it correctly. Faced with a variety of chemical languages, teachers require standardized, accurate and rigorous use of chemical languages in daily teaching to help students form the habit of using chemical languages correctly. However, there are still some teachers who don't pay much attention to the standardized use of chemical language in teaching. For example, some teachers are used to saying that "1 sodium hydroxide contains 1 sodium atom". Because sodium hydroxide is an ionic compound without molecules, the use of chemical language is not standardized and rigorous. If students learn this expression, it will have a bad influence on their future study. Therefore, chemistry teachers should focus on analyzing and comparing some easily confused chemical concepts and terms, so as to clarify the learning ideas for students; Starting with the details, we should standardize students' correct use of chemical language and strengthen their inspection and guidance.
(B) to establish the basic concepts of chemistry
Chemistry teaching should focus on cultivating students to establish scientific and comprehensive basic concepts unique to chemistry, so as to lay a good foundation for cultivating students' core literacy.
The first is to cultivate students' microscopic concepts. Chemistry studies the composition and changing laws of matter from microscopic particles such as atoms and molecules. Only from the microscopic point of view can we find the changing laws and characteristics of substances and master the essence of chemical reactions. Many students find chemistry difficult to learn, which has an important relationship with their failure to establish a micro-learning concept. Therefore, it is necessary for students to establish the concept of micro-learning, and pay attention to linking micro-concepts with macro-concepts in order to better understand chemical knowledge.
The second is to establish the concept of saving. Conservation of matter is an important law in chemistry, and it is also an essential basic concept for students to learn chemistry. Only by studying and understanding chemistry from the concept of material conservation can we effectively solve chemical problems. Especially for many chemical calculation problems, it is easy to solve them by using the idea of material conservation. Conservative thinking method is an important thinking method in chemistry and an important content of core literacy. Therefore, it is necessary to cultivate students to firmly establish the concept of material conservation and be consistent in their study, and on this basis, expand the conservation thinking method to knowledge points such as mass conservation, charge conservation, electron conservation, volume conservation and concentration conservation.
(C) to cultivate chemistry learning ability
The learning method of chemistry has something in common with other disciplines, but it also has its own characteristics. Mastering good learning methods can improve learning efficiency and promote students' chemistry learning ability. For example, the commonly used learning methods are: comparison, analogy, classification, analysis, induction, reasoning and so on. To improve chemistry learning ability, we must pay attention to the cultivation of students' independent inquiry learning ability, especially the cultivation of chemical thinking ability, so that students can construct chemistry knowledge independently on the basis of mastering correct methods, which is very important to cultivate students' chemical core literacy.
For example, in the course of "Ordinary Alkali", in order to let students know the essence of alkali from macro, micro and chemical language, the following situations can be created for students to explore and learn: (1) Add appropriate amounts of Na OH and Ca (OH) 2 solutions into two test tubes respectively, and then drop a few drops of Cu SO4 solution respectively to observe the phenomenon. (2) Put an appropriate amount of sodium hydroxide solution into the beaker, then pour an appropriate amount of copper sulfate solution, and then analyze which ions in the two solutions have reacted. Which ions do not participate in chemical reactions? (3) Write the chemical reaction equation in scenario (2) to explain which ion generates blue flocculent precipitate. Let students use the situation (1) to operate and observe the essence of the reaction between alkali and salt from a macro perspective; Case (2) is to analyze the essence of the reaction between alkali and salt from the microscopic (ionic) point of view; Situation (3) The writing of chemical equations is to grasp the essential characteristics of the two reactions of alkali and salt from the perspective of chemical language. In this way, students can master the methods of chemistry learning and the knowledge points of "alkali solution+salt solution → new salt+new alkali" from different aspects.
(D) Attach importance to the ability of chemical experiments
The ability of chemical experiment is of great significance to cultivate students' core literacy. The experimental ability of chemistry class is not only an operational skill, but also helps students to deepen their understanding of chemical knowledge and form chemical thinking methods. Therefore, in chemistry teaching, teachers should pay attention to strengthening chemistry experiment teaching, creating experimental conditions for students, cultivating students' correct operation skills, guiding students to carry out experimental exploration, and letting students master the complete experimental process.
For example, in order to explore whether there is a chemical reaction between Na OH and CO2, the following series of experiments can be designed for students to explore: (1) Put an appropriate amount of Na OH and clarified limewater solution into two test tubes respectively, then introduce CO2 gas respectively, observe the experimental phenomena and analyze the experimental results. It can be seen that there is no obvious change in the test tube added with Na OH, so it is impossible to judge whether the reaction has occurred, but the lime water solution is turbid, indicating that the reaction has occurred; (2) Put an appropriate amount of Na2CO3 solid in the test tube, and then add an appropriate amount of distilled water to observe the change of the solution. It can be seen that Na2CO3 is soluble in water, so it is inferred that (1)na2co 3 may be generated by chemical reaction between Na OH and CO2 in the experiment, but it is soluble in water, so there is no obvious phenomenon. (3) Check whether Na2CO3 is generated. In the experiment (1), drop an appropriate amount of dilute hydrochloric acid into the solution to observe whether bubbles are generated. It can be seen from observation that Na2CO3 reacts with HCl to generate CO2, which proves that "Na OH can react chemically with CO2".
(E) Cultivate chemical values
Infiltrating scientific attitude in chemistry teaching and cultivating students' world outlook and values such as green chemistry thoughts are important contents of core literacy, which is of great significance to students' growth and training high-quality talents. Looking at the requirements of junior high school chemistry textbooks and curriculum standards, it is an important purpose of chemistry teaching to cultivate students' scientific attitude and green chemistry thought. Therefore, we should pay attention to cultivating students' correct chemical values in teaching, so that students can gradually develop a scientific and rigorous learning attitude and establish a green chemistry idea of environmental protection and sustainable development. For example, in order to cultivate students' rigorous scientific attitude, sodium hydroxide can be used to react with copper sulfate solutions with different concentrations. Textbooks point out that blue Cu (OH) 2 precipitate can be formed, but if the concentration of copper sulfate solution is too low, green precipitate will appear in the solution. Without a realistic and rigorous scientific attitude, it is impossible to correctly analyze this phenomenon.
To sum up, in junior high school chemistry teaching, it is of great significance to cultivate students' core literacy for their long-term and all-round development. In teaching, teachers need to deeply understand and master the connotation and teaching requirements of the core literacy of chemistry, and comprehensively improve students' core literacy of chemistry.