How to improve the effectiveness of chemistry experiment teaching in junior high schools

Being based on experiments is the basic feature of chemistry teaching. Experiments provide students with a cognitive background for chemical learning. They not only help students form chemical concepts, understand chemical laws and principles, but also stimulate them. Interest in chemical learning and inquiry. Experimental teaching can have a positive and effective effect on inspiring students' thinking, cultivating scientific methods and innovative spirit. Therefore, how teachers can effectively design and implement experimental teaching and promote students to improve the effectiveness of chemistry learning is a very critical link in the reform of chemistry teaching in middle schools. Let’s talk about my personal experience on strategies to improve the effectiveness of experiments.

1. The change of teaching concepts is the prerequisite for the effectiveness of the new curriculum experiment

I believe that only by strengthening the effectiveness of experimental teaching can we achieve the expected training goals of the new curriculum and achieve the expected training goals of the new curriculum. Truly enable students to develop learning methods and habits of "independent learning, cooperative learning, inquiry learning, and hands-on practice". Therefore, teachers should change their teaching concepts and establish new teaching concepts: ① Teaching should be closely connected with students’ living world, so that the teaching content is connected with the living world; ② Teachers’ teaching methods should serve students’ learning styles; ③ Focus on making students understand , inquiry, give students space to think freely, and help students discover the personal significance of learning knowledge; ④ Teachers should create a harmonious and harmonious learning atmosphere and establish an equal teacher-student relationship; ⑤ Teachers should encourage students to expand their knowledge and establish learning goals , improve comprehensive learning ability. Only by effectively strengthening the chemistry experimental teaching under the new curriculum can experimental teaching play an effective role.

2. Create effective experimental scenarios to improve students’ initiative and enthusiasm for learning chemistry

1. Appropriate use of multimedia technology to make the demonstration experiment more vivid and intuitive, and the effect more optimized . For example:

In the "Reaction of Carbon Monoxide and Iron Oxide" experiment in the junior high school chemistry textbook (Shanghai Education Edition), at the beginning of the experiment, carbon monoxide should be introduced first and then the glass tube should be heated. When the teacher asked: What would be the result if these two steps were reversed? The students talked a lot and the discussion was lively. So I used an animation to play the explosion phenomenon that occurs when carbon monoxide is first introduced and then heated. The students were deeply impressed and remembered it vividly.

2. Use experimental scenarios to stimulate curiosity and improve students’ initiative and enthusiasm for learning chemistry

Curiosity is the beginning of creative behavior and the driving force for students to explore psychology. In creativity Thinking has the role of triggering and catalyzing, thus becoming one of the intrinsic motivations for students' behavior. Einstein said that he had no special talents, only a strong curiosity. When students are curious about things, creative thinking often bursts out. Therefore, chemistry teachers should be good at using experiments, carefully create chemical scenarios, and stimulate students' strong interest in inquiry. Then the cultivation of inquiry consciousness will be a matter of course. For this reason, taking the first chemistry lesson well has a great impact on junior high school students. Because students often enter the chemistry hall with a kind of curiosity. They look forward to unveiling this mysterious veil and falling in love with chemistry as a new subject. For example, when teaching the first chemistry class, the teacher can introduce to the students at the beginning: "From today on we will start learning a new course"

And release the pre-filled hydrogen balloon to Above the classroom, a slogan is tied under the hydrogen balloon that reads: Learn Chemistry Well. At this time, the students were in high spirits and the classroom was filled with a cheerful atmosphere. The teacher asked: "Why can the hydrogen balloon fly upward?" "

If we use a mouth-blown balloon instead, can it fly upward?"

For these questions, the teacher does not need to answer, but can also ask a series of questions: How is steel made? Why does iron rust? Why does gas kill people? What properties of drugs can be used to treat hyperacidity in the human stomach? How to prevent forest fires? etc. Continuously raise problems in front of students that they cannot solve yet, so that students can generate a strong desire for knowledge among endless problems, so that they are never satisfied and keep making progress in the learning process.

At the same time, you can also use modern teaching methods and use "video introduction" to catch students' attention, present the colorful first impression of the chemical world, and expand students' horizons for knowledge; you can also design several interesting experiments, such as "igniting or not burning" Interesting chemistry "magic" such as "handkerchief", "rain falling, flowers blooming and green leaves emerging", "smoke in the air", etc. Students are eager to know: What is going on? Why does this happen? Can you operate it yourself? From then on, students became highly motivated and interested in learning chemistry. You can even create scenarios such as short stories, scientific historical facts, and real objects to stimulate students' curiosity and desire to further explore and learn, so that they can feel the joy of learning chemistry. Because when you have curiosity, you will have questions, and when you have questions, you will have the desire to learn. Only with the desire to learn can we truly stimulate students' intrinsic motivation to learn, and actively acquire knowledge independently, turning "I want to learn" into "I want to learn," which enhances the effectiveness of experimental teaching.

3. Improve the effectiveness of experiments by combining new curriculum teaching with the need to cultivate students' abilities

1. Change demonstration experiments into exploratory experiments to cultivate students' innovative abilities.

In the past, classrooms Demonstration experiments generally involve teachers as the main body, and students are just spectators without direct participation. This is not conducive to the cultivation of students' innovative abilities. The current new curriculum chemistry teaching changes "creative teaching" to "creative learning" for students, and demonstration experiments are replaced. Change it to an exploratory experiment, allowing students to fully use their brains, hands, and words to play their main role. For example, in the teaching of "Preparing Oxygen", you can use exploratory experiments to learn about the laboratory preparation method of oxygen. Experimental teaching allows students to learn about different aspects of oxygen production using potassium permanganate and hydrogen peroxide, thereby mastering the relevant knowledge of oxygen production in the laboratory. This kind of experimental teaching that changes the demonstration experiment into an exploratory experiment is conducive to students' creativity. Stimulate thinking and cultivate students' innovative abilities.

2. Use a variety of experimental methods to activate and cultivate students' thinking abilities.

① Experimental gamification: "education through fun". It is a basic principle of youth education. The enlightenment education of each of us starts from games. Therefore, in the chemistry experiment teaching of "using simple experimental methods to distinguish cloth made of cotton fiber, wool fiber and synthetic fiber" It allows students to learn through games and achieve the best state of learning.

② Some demonstration experiments can be made into some courseware, and the re-visibility of audio-visual teaching facilities such as computers and projectors can be used to focus on learning. The basic situation of the experiment is presented, so that students can visualize abstract knowledge and better understand the knowledge and content. For example, the experimental teaching of "Reducing Iron from Iron Oxide Using Experimental Methods" can be used due to the limitations of experimental conditions. The methods of model display and animation demonstration allow students to be immersed in the situation and master knowledge.

③ For students’ group experiments, on the basis of helping students master the experimental principles, we should encourage students to think seriously and be brave enough to practice. Allow students to conduct experiments using different experimental principles, multiple instruments, drugs, and different experimental procedures; allow teachers to cultivate students' adaptability according to different experimental situations. For example, for several substances such as H2, etc. in middle school chemistry teaching. p>

For laboratory preparation of O2, Cl2, CO2, NH3, etc., students should be guided to think and analyze from the aspects of reaction principles, reactant states, collection methods, preparation devices, etc., to find the best solution. Cultivate students' adaptability.

3. Cultivate students' exploratory spirit of active research and the ability to creatively discover, think and solve new practical problems through close observation of daily life phenomena and diligent thinking. /p>

Closely combine students' daily life and industrial and agricultural production, and raise a series of practical questions, such as the research study topic in the chemistry textbook "Investigating the performance, price, resource storage of fuels used by households and the environmental impact of combustion products" influence, put forward their own opinions on the choice of household fuels and how to make them fully burn", "investigate the main types and recycling value of solid waste in the region", etc. Teachers should guide students to conduct exploration based on their existing knowledge and life experience, and propose solutions to practical problems.

This can stimulate students' interest in learning, seeking knowledge, and exploration, enable them to actively learn knowledge, and cultivate students' ability to flexibly use chemical knowledge to solve practical problems.

4. Pay attention to the process of experimental inquiry and cultivate scientific literacy

Actively carrying out scientific inquiry activities can change students' learning methods, so that students can acquire chemical knowledge and skills while being influenced by science. Method training, experience the fun of inquiry, and form and develop inquiry abilities. For example, in the knowledge teaching of "quantitative understanding of chemical changes" in junior middle school chemistry, the chemical experiment inquiry process designed by the teacher in the teaching process is: "Create situations and ask questions" (Does the total mass of a substance change before and after chemical changes? Is it an increase? Increase, decrease or remain unchanged?)

"Propose a hypothesis and design an experiment" (After a substance undergoes a chemical change, its total mass remains unchanged)

"Conduct an experiment and observe the experiment" (Add copper sulfate solution to a closed container, then add sodium hydroxide solution drop by drop, and observe whether the masses before and after the reaction are equal; add marble and dilute hydrochloric acid to a closed container, fully react with the released gas, and then use clarified lime Water absorption, observe whether the mass is equal before and after the change)

"Students discuss, inspire thinking"

"Communicate and express, expand migration" (Conclusion: Before and after the chemical change of the substance, the total mass remain unchanged). It is under the inspiration and guidance of teachers that the exploratory experimental teaching is successful and opens up students' ideas. After the students experiment, think and analyze this series of exploratory questions, they can derive the law of mass conservation