Reflection on Molecular and Atomic Teaching

Part 1: Reflection on Molecular and Atomic Teaching

The concept of molecules and atoms is the first lesson in which chemistry enters the microcosm and is the most difficult lesson to understand. Today, the first lesson successfully explained the concept of molecules and atoms and the essence of chemical changes. The feelings are better. The special records are as follows:
Multimedia teaching brings unprecedented benefits to our traditional teaching, but sometimes many teachers are often limited to multimedia and ignore the effects of clear textbooks. Many teachers of molecules and atoms use multimedia animation to demonstrate the microscopic process of chemical changes, and the effect is good. Before the class, I also did very good courseware, but before class, I was prepared to talk about the courseware, because it would distract the students because our students were more distracted in class. Fully focusing on the lectures is the key to the success of this lesson. I used the molecules and atoms drawn from the board to explain the evaporation of water and the electrolysis of water. At the same time, I also analyzed the C60 molecular model to be used here. The molecules are made up of atoms. The students also listened very well. They can fully cooperate with the teacher's explanations, let the students feel, experience, recognize and learn from multiple aspects. "Molecule is the smallest particle that keeps the chemical properties of matter." Atom is the smallest particle in chemical change. "Understand the relationship between molecules, atoms, and matter: matter is composed of molecules or atoms. Molecules are composed of atoms. The molecules and atoms drawn by them can be well analyzed. The essence of material chemical changes, such a summary, the students fully grasp and understand, the overall effect is very good!

Part 2: Reflection on Molecular and Atomic Teaching

We all know that there are three basic particles that maintain the chemical properties of matter - molecules, atoms, ions. The molecules appear first in the teaching, and then the atoms and ions appear one after another. When atoms and ions appear in teaching, it is necessary to ask students that particles that maintain the chemical properties of matter, in addition to molecules, also have two kinds of particles, atom and ion. At this time, it is easy for students to compare the three particles. For the middle school students, their microscopic imagination is limited, so many students have obstacles to understanding. For example, some students will ask: "Teacher, the molecule is the smallest particle that keeps the chemical nature of matter, what about the atom?" At this time, I will use a lot of relevant content to explain to them. But many times after the students listened, I can see from their expressions: they didn't fully understand. Because for middle school students, they have just been exposed to chemistry, so it is really difficult to make them understand. Moreover, the current rural teaching has not yet reached the level that can bring courseware production and online teaching to the classroom to help students "imagine".
In fact, I believe that the three kinds of particles, such as molecules, atoms and ions, can maintain the chemical properties of the substance only when they directly constitute a substance. They can't be put together at all for irrelevant size comparisons, and they also create obstacles to understanding to some extent. Therefore, I still agree with the old textbook: the molecule is a kind of particle that keeps the chemical properties of the substance. This is the most appropriate, because the particles that keep the chemical properties of the substance have atoms and ions in addition to the molecules! In this way, students are easy to understand.
The definition of "atom" is: an atom is the smallest particle in a chemical change.
I feel that this statement is not proper. Because when I talked to students about "ionic compounds and covalent compounds," the formation of shared electron pairs and electrons occurred during the formation of water and NaCl. As a result, some students after class asked me: "Teacher, isn't that the atom can't be divided again in the chemical reaction? In the reaction of 2H2+O2=2H2O, how to separate the electrons from the atom, and also formed Sharing the electron pair, in 2Na+Cl2=2NaCl, also 'running' the electron transfer from the atom?" I am ok. Because it is true.
Therefore, I believe that in the study of chemistry in the middle school, for the middle school students in the primary stage and the enlightenment stage, how to give a better definition of "molecular, atomic" can help them to understand and accept these microscopic particles more easily. , is very necessary.

Part 3: Reflection on Molecular and Atomic Teaching

1. In the teaching of this lesson, the most difficult thing I feel is the example. It is necessary to ensure that the microcosm is reflected in this lesson. This example can make students have a long-term impression of the characteristics of the microcosm.
2. Because this lesson belongs to the micro world, it is very abstract for students. It is difficult for students to understand the true meaning of molecules and atoms. How to stimulate their interest is that I must think about it before I can carry out this class. Of course, after actual teaching, some students still can't understand the macro and micro of matter.
3. When teaching this class, I feel that we should increase the intensity of the experiment and let the students boldly guess through experiments. For example, in addition to the experiment of magenta in the book, an experiment in which red ink moves in water, an experiment in which sucrose is dissolved, and an experiment in which 10 ml of water and 10 ml of alcohol are mixed can be performed.
4, in the teaching of this lesson, it should also be difficult, let students love chemistry, know how to learn chemistry.

Part 4: Reflection on Molecular and Atomic Teaching

In teaching, I first use the air freshener to smell the flowers, let the students feel the wind on the face, and draw the theme of this lesson. From these examples happening to the students, I realize that the matter is composed of particles. As long as you carefully observe it, you can feel its existence. Using the curiosity of the students, new knowledge has been introduced and the students' interest in learning has been stimulated.
Secondly, guide students to think boldly based on phenomena and conduct experiments to explore the nature of molecules. Taking the illustration of the benzene molecule and the mass of the water molecule and the number of molecules in a drop of water, the students intuitively feel that the mass and volume of the molecule are small. Taking the diffusion of magenta as an example of demonstration experiments and ammonia molecular diffusion experiments, it is pointed out that the molecules are constantly moving. Whether the "1+1" is equal to the syringe pumping test is compared and verified, and the image shows that there is a gap between the molecules.
Finally, six students were selected to perform, acting as hydrogen atoms and oxygen atoms, respectively, to interpret the microscopic process of electrolyzed water. Make the abstract micro-knowledge more vivid, let the students deeper experience, the essence of chemical change in the whole process, the main line of inquiry teaching, constantly develop the students' thinking, truly achieve the theory and practice, become abstract into reality It is difficult to make it easier. It not only deepens students' understanding of knowledge, but also cultivates students' abstract thinking ability, imagination and analysis, reasoning ability, and enables students to experience the process, method and joy of inquiry, so that students can get close to chemistry and love chemistry. I am eager to learn more about the emotions of chemistry and to build confidence in learning chemistry.
Success:
1. Students' experimental phenomena are obvious, which not only stimulates students' interest, but also inspires students' thinking and enhances students' basic operational skills;
2. In this subject, because of the sound painting, type, and style, the image is lively, the abstract knowledge is concrete, and the complex knowledge is clear. Students can experience the chemical change. In fact, the molecules are divided into atoms and atoms and then recombined into new material molecules. The process of paving the way for an in-depth understanding of important concepts such as chemical changes, physical changes, molecules, and atoms;
3. The final design exercises for students to rationalize the fundamental differences between physical and chemical changes using molecular and atomic perspectives, and rationalize the concepts, relationships, and fundamental differences between molecules and atoms, so that students can accept these relatively easily and happily. Abstract knowledge.
Inadequacies:
This lesson reflects that students don't know much about the chemicals around them, and don't pay enough attention to common chemical phenomena. For some more complicated examples, it is difficult to describe them in appropriate language. Therefore, in the teaching, teachers need to guide students to divergent thinking, consider problems from all aspects and multiple angles, describe problems, cultivate students to see the essence through phenomena, and imagine the imagination and innovation ability of the micro world from the giant phenomenon.
From the teaching of this class I feel:
1. Our concept teaching must follow the students' cognitive habits.
2. Our explanation must come from life and to life.
3. Grasp the outline and review the textbooks.
Specifically:
1. The cognitive habits of students are from shallow to deep, step by step, and can't think of eating a big fat man. The idea of ​​one step is impossible to achieve in middle school teaching.
2, the way students accept knowledge is "first modeling, then abstract, and finally used, and must be used in small steps, gradually improve."
3, chemistry learning can not be separated from life, to give more examples, find the law from it, remember not to be too abstract.
4. It is also necessary to properly integrate knowledge. At a stage, it is necessary to use the new knowledge learned recently to upgrade the old knowledge.

Chapter 5: Reflections on Molecular and Atomic Teaching

The content of this lesson is the second element of the ninth grade of Guozhong Chemical, the "Water of Nature" topic 2 molecules and atoms. In order to distract the teaching difficulties, I divided the subject into two lessons, and the first lesson only talked about molecules. Learn the knowledge of the atom in the second lesson.
The numerology section is the beginning of the student's entry into the micro-world from the giant world. It is also the key to solving the chemistry teaching difficulties—the micro-interpretation of the phenomenon of the giant view, or the basic knowledge and tools that are indispensable for continuing to learn the chapters of chemical equations and solutions. However, due to the abstraction of this part of the knowledge, improper handling will weaken the interest of students and become a differentiation point for students' learning. For this reason, I first create a problem situation with the common phenomena in students' daily life, introduce new lessons, and strive to make students easy. A happy mood enters the classroom. Let the students imagine, analyze and discuss, and finally clearly recognize that the molecules are small, small and always moving. Followed by: creating a problem scenario that leads the way, leading to factors that affect the speed of molecular movement. The demonstration experiment of magenta diffusion was changed to a student hands-on experiment. Let the students experience the authenticity of the experiment for themselves, and the teacher is not saying that it is awkward. Finally, through multimedia courseware, life examples make students further realize that molecules are constantly moving, and the rate of movement is related to temperature. Furthermore, the question of whether "1+1 must be equal to 2" immediately aroused the curiosity of the students because it has broken the mathematical simple addition. Because the volume of 100ml water and 100ml alcohol is less than 200ml, it is difficult for students to understand and cannot be accurately analyzed. Therefore, I designed a huge-scale simulation experiment with simple operation and high visibility. The mixture of soybean and millet is easy to understand by the analog students. There are gaps between the particles, which makes this teaching difficult to break through. At the same time, it also focuses on inspiring students to make full use of household products to complete the experiment, so that the classroom strives to live and naturalize, and let students design themselves as masters of learning and let students transform their thinking. ——To do research and experiment, not necessarily into the laboratory, life is a big classroom.
The teaching of molecular concepts is another difficulty in this lesson, so I use the creation of problem situations and animation courseware - water power decomposition, allowing students to fully discuss the concept of molecules.
In this teaching process, the classroom atmosphere is active and the teaching effect is good. At the same time, I also feel that the use of multimedia teaching methods is vivid and vivid, which reduces the burden for teachers. It is very beneficial for students to understand microscopic and abstract knowledge. The students' perceptual knowledge helps students to think rationally, and thus summarizes the essence and law through phenomena. It mobilizes the enthusiasm of students' thinking, and makes the transition from "normal" to "excited state", thus sparking the thinking. Finally, the layout of the exercises I strive to come from life, to make the knowledge life, let the students feel that the chemistry is around, and also make the students have a qualitative leap in the understanding of the molecular nature.