Author: Wei

Abstract: Attention should be paid to experimental teaching in chemistry teaching. Teachers should strive to carry out experimental teaching, change all kinds of traditional experimental teaching, use classroom experiments to improve students' interest in learning, increase interesting experiments to stimulate students' innovative thinking, and carry out family experiments to cultivate students' innovative ability.

Keywords: improving experimental teaching practice

Chemistry is a natural science based on experiments, and experiments are the basis of chemistry teaching. Teaching can not only enable students to acquire scientific knowledge and skills, but also help to cultivate students' scientific methods, experimental ability and innovative spirit, and cultivate students' rigorous and realistic attitude, scientific spirit of pursuing truth and scientific values. Experimental teaching is an important link in the whole middle school chemistry teaching process and an indispensable way to cultivate students' scientific literacy and enhance their innovative ability. If students are allowed to do experiments and practice repeatedly, their learning enthusiasm and initiative will be greatly improved, which is irreplaceable by any other teaching form and method. However, in the actual chemistry teaching, for various reasons, experimental teaching has always been a weak link, resulting in many students' poor practical ability. If teachers can give full play to the characteristics of the close connection between chemistry and real life in teaching, and slightly improve some experiments in teaching, such as demonstration experiments, students' family experiments, interesting experiments, etc., they will receive unexpected results. Based on my own teaching practice, this paper talks about some improvements in junior middle school chemistry experiment teaching.

First, change teachers' demonstration experiments into students' in-class experiments to cultivate students' experimental skills.

Students who do experiments in person are more impressed than teachers who demonstrate their observations. At this time, students have changed from observers to operators and experimenters, and their excitement, positive attitude and initiative in thinking are obvious. It can be seen that students can not only achieve the purpose of demonstration experiments, but also make up for the shortcomings of demonstration experiments. Therefore, this form should be adopted more often when conditions permit. Generally speaking, demonstrations that are simple, time-consuming, safe and reliable, and do not pollute the environment can be changed into in-class experiments. For example, the determination of oxygen content in the air, the experiment of molecular properties, the experiment of oxygen properties, the dilution of concentrated sulfuric acid, the properties of acid, alkali and salt, etc. In class, teachers should put forward requirements in time to help students, so that students can gradually master the essentials and principles of experimental operation by doing experiments. In this kind of in-class experiment, students gradually learned to observe, analyze, summarize, summarize and reflect, and at the same time their experimental skills were improved.

Second, increase interesting experiments to stimulate students' innovative thinking

In classroom teaching, sometimes in order to adjust the classroom atmosphere, mobilize students' enthusiasm and initiative, enhance students' interest in learning, eliminate students' learning confusion, and help students deepen their understanding and memory of knowledge, some interesting demonstration experiments can be appropriately supplemented according to the actual situation, which will have unexpected effects on stimulating students' innovative thinking. For example, in the introductory class, in addition to several experiments in the textbook, the volatilization of ammonia water can make colorless phenolphthalein test solution turn red, which can be used as "Cycas", petals can be used as alkali indicator, iron can be used as "copper tree", and carbonate can be used as dilute acid to identify the authenticity of pearl necklaces. For example, when reviewing the properties of carbon dioxide, experiments such as "magnesium burning in carbon dioxide", "fountain of sodium hydroxide solution" and "ball expanding in a closed bottle" can be added. These experiments not only increase students' deep understanding of the nature of carbon dioxide, but also enable students to learn more knowledge. In addition, when doing demonstration experiments, instruments, drugs and operation methods can be further improved according to specific conditions. For example, the catalytic experiment of manganese dioxide, the laboratory preparation of oxygen and the experiment of reducing copper oxide with carbon monoxide are several typical examples. Before using the improved device to do experiments, students must know what the advantages of this improvement are. Thinking about how to improve at the same time can stimulate students' divergent thinking, innovative thinking and enthusiasm for learning, and make students realize that innovation is not mysterious. As long as they study hard, innovation will accompany their life and study.

Third, encourage students to actively carry out family experiments and cultivate their innovative ability.

Carrying out small family chemistry experiments is the continuation, expansion and deepening of classroom teaching. For example, let students collect discarded beverage bottles, disposable syringes, infusion tubes, straws and so on. Making reaction instruments in daily life; A series of family chemistry experiments can be designed by replacing carbonate with eggshells and pebbles and replacing acid with vinegar. For example, after the first section of the first chapter, "Determination of oxygen content in the air", students are assigned such a family experiment; Using the materials around us, it is verified that the oxygen content in the air is 265438 0% (volume content), and the experimental results are analyzed and summarized. After returning home, most students will use cups instead of bells, small pots instead of sinks, and small candles instead of red scales for repeated experiments. The experiment was successful, and the operation essentials were summarized: the experiment was unsuccessful, and what caused it was analyzed. Even in the same experiment, students designed different bills according to different equipment. The advantages and disadvantages of different schemes are compared through experiments. In this kind of family chemistry experiment, students can choose different equipment and make different designs from different angles and levels, which inevitably includes the cultivation of students' innovative consciousness, innovative spirit and innovative ability. In the long run, it is bound to achieve the goal of cultivating students' innovative ability.

In chemistry experiment teaching, whether it is supplementary experiment or improvement experiment, all starting points should be designed around the development of students, so that students can learn while doing, thus improving their experimental ability and innovation ability.

References:

1, "into the classroom-junior high school chemistry" 2004 1 1 Higher Education Press.

2, junior high school version of the chemistry course teacher discipline training materials in June 2004, Peking University Publishing House.

3. The new curriculum concept and junior high school chemistry curriculum reform, 2002 Northeast Normal University Press.