Objectives (5 minutes)

1. Understanding the concept of atomic model: Students should be able to understand what an atomic model is and how it is used to represent the structure of an atom. This includes understanding that a model is a simplified representation of reality and that different models are used in different contexts.

2. Knowledge of the main atomic models: Students should be able to identify and describe the main atomic models throughout history, starting with Dalton's model and ending with the current model, the quantum model. They should be able to explain the main characteristics of each model and how they have evolved over time.

3. Critical analysis of atomic models: Students should be able to evaluate the strengths and weaknesses of each atomic model and how they have contributed to our current understanding of atomic structure. This involves the ability to think critically and argue in a well-founded manner.

Secondary Objectives

• Application of acquired knowledge: Students should be able to apply the knowledge they have acquired about atomic models to solve problems and answer questions in a classroom context.
• Development of research skills: Students should be able to research and collect information about atomic models autonomously and effectively. This includes the ability to evaluate the reliability and relevance of sources of information.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher starts the lesson by reviewing the basic concepts of atoms, including their structure, subatomic particles (protons, neutrons, and electrons), and the idea that atoms are the fundamental unit of matter. This will serve as a solid foundation for the discussion of atomic models that will follow. (3 - 5 minutes)

2. Presentation of problem situations: The teacher presents two situations that challenge students' understanding of atomic structure. The first one could be the question: "If atoms are so small, how can we know what is inside them?" The second one could be: "If atoms are the fundamental unit of matter, why are there different types of matter?" These questions serve to arouse students' curiosity and prepare them for the topic of the lesson. (2 - 3 minutes)

3. Contextualization of the importance of the topic: The teacher explains how the study of atomic models is crucial for understanding many chemical and physical phenomena. He may mention that, without understanding atomic structure, we would not have been able to develop technologies such as computers, cell phones, and medications. Additionally, the teacher may mention that the evolution of atomic models reflects the nature of science, which is a continuous process of theory building and revision. (2 - 3 minutes)

4. Introduction of the topic with curiosities and applications: To capture students' attention, the teacher can share some curiosities and applications related to the topic. For example, he may mention that Bohr's atomic model, which describes electrons orbiting the nucleus in specific layers, was inspired by the movement of planets around the sun. This can be followed by a discussion of how atomic models are used in medicine, for example, in understanding radioactivity and creating magnetic resonance imaging. (3 - 4 minutes)

Development (20 - 25 minutes)

1. Atom Modeling Activity (10 - 12 minutes):

   • Instructions for the activity: The teacher will divide the class into groups of 3 to 4 students and provide each group with materials such as cardboard, colored pens, modeling clay, and toothpicks. Each group will create a three-dimensional model of an atom, representing the subatomic particles (protons, neutrons, and electrons) and their distribution in the electron shells.
   • Guidelines for creating the model: The teacher will guide the students to research the atom they will model, including the number of protons, neutrons, and electrons, as well as the distribution of these particles in the electron shells. They should use the provided materials to create a model that faithfully represents the researched information.
   • Presentation of the models: After the models are completed, each group will present their atom to the class, explaining the characteristics of the modeled atom and how they were represented in the model. The teacher will ask questions to ensure students' understanding of atomic structure.

2. Debate Activity on Atomic Models (10 - 12 minutes):

   • Preparation for the debate: The teacher will divide the class into two groups, "Protons and Neutrons" and "Electrons," and provide each group with information about a specific atomic model (for example, Dalton's model and the Rutherford-Bohr model). Each group will have time to prepare arguments that defend their model and refute the opposing group's model.
   • Conducting the debate: After the preparation, each group will present their arguments to the class. After each presentation, the opposing group will have the opportunity to refute the arguments presented. The teacher will act as a moderator, ensuring that the debate is respectful and that all students have the opportunity to participate.
   • Discussion after the debate: After the debate, the teacher will lead a classroom discussion, highlighting the strengths and weaknesses of each model and how they have contributed to the evolution of understanding atomic structure.

3. Research Activity on Atomic Models (5 - 6 minutes):

   • Instructions for the activity: The teacher will ask students to individually research an atomic model that was not discussed in the previous activity (for example, the quantum model). They should note the main characteristics of the model, how it differs from other models, and why it is considered the current model.
   • Sharing of findings: After the research, students will share their findings with the class. The teacher will complement the information, ensuring that all students have a complete and accurate understanding of atomic models.

Return (10 - 15 minutes)

1. Group Discussion (5 - 7 minutes):

   • The teacher asks each group to share the conclusions or solutions they reached during the atom modeling activity and the debate on atomic models. Each group will have up to 3 minutes to present their main findings.
   • During the presentations, the teacher should encourage other groups to ask questions and provide feedback. This will help promote discussion and exchange of ideas among students.

2. Connection to theory (3 - 4 minutes):

   • After all presentations, the teacher will provide a general review, connecting the groups' findings with the theory of atomic models.
   • The teacher will highlight the main ideas and concepts that emerged from the practical activities, reinforcing how they relate to the evolution of atomic models over time.

3. Individual Reflection (2 - 3 minutes):

   • The teacher will ask students to individually reflect on what they learned during the lesson. They should think about the most important concepts they learned and what questions have not been answered yet.
   • Students will have one minute to write their reflections. The teacher may suggest some questions to guide the reflection, such as: "Which atomic model impressed you the most and why?" and "What questions do you still have about atomic models?"

4. Sharing of reflections (2 - 3 minutes):

   • The teacher asks for volunteers to share their reflections with the class. They will have up to a minute to express their ideas.
   • The teacher encourages other students to listen attentively and respect their classmates' opinions. He may also provide feedback and clarify any misunderstandings that may arise.

5. Closure (1 minute):

   • To conclude the lesson, the teacher recaps the main points that were discussed and reinforces the importance of studying atomic models for understanding the structure of matter.
   • He may also suggest additional reading materials or videos so that students can deepen their knowledge on the topic.

Conclusion (5 - 7 minutes)

1. Lesson Summary (1 - 2 minutes): The teacher starts the Conclusion by recalling the main points covered during the lesson. He highlights the evolution of atomic models, starting with Dalton's model and ending with the current quantum model. The teacher also reinforces the importance of each model, explaining how they have contributed to our current understanding of atomic structure.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes): The teacher emphasizes how the lesson connected the theory of atomic models with practice through the atom modeling activities and the debate. He also highlights the practical applications of studying atomic models, such as their relevance to the development of technologies and the understanding of chemical and physical phenomena.

3. Extra Materials (1 - 2 minutes): The teacher suggests reading materials and videos that can help students deepen their knowledge of atomic models. For example, he may recommend reading specific chapters of a Chemistry textbook or suggest watching an animated video that explains the different atomic models clearly and concisely.

4. Importance of the Subject (1 minute): Finally, the teacher reinforces the relevance of the subject covered for students' daily lives. For example, he may mention that understanding atomic structure is essential to grasp how the materials around us work and to appreciate the wonders of science and technology. Additionally, the teacher may highlight that studying atomic models also has philosophical implications, helping us reflect on the nature of reality and how humans construct knowledge.