Objectives (5 - 7 minutes)

1. Understand the nature of the physical states of matter: The teacher should encourage students to reflect on how matter manifests in our daily lives, presenting problem situations involving the different physical states. Students should be able to recognize that matter can be in different states depending on temperature and pressure conditions.

2. Distinguish between solids, liquids, and gases: Students should be able to differentiate between the three main physical states of matter. The teacher should present the distinct characteristics of each state and propose practical activities that allow students to identify these differences.

3. Relate molecular structure to the physical states of matter: After understanding the different physical states, students should be able to relate them to the molecular structure of materials. The teacher should provide concrete examples and explain how the molecular structure affects the physical properties of materials.

Secondary objectives:

• Develop observation and experimentation skills: Through the proposed practical activities, students should develop observation and experimentation skills, essential for the study of chemistry.

• Stimulate curiosity and critical thinking: The teacher should encourage students' curiosity, promoting questioning and critical thinking. This can be done through classroom discussions and the presentation of natural phenomena related to the physical states of matter.

Introduction (10 - 12 minutes)

1. Review of previous contents: The teacher should start the lesson by reviewing the concepts of matter and its properties, such as mass and volume. This review is essential for students to understand and apply the concepts that will be presented during the lesson. (2 - 3 minutes)

2. Problem situation 1: The teacher can propose the following situation: 'Imagine you have an ice cube. What happens to it if you leave it in a room for a while?' The idea is for students to reflect on how a change in temperature can affect the physical state of matter. (2 - 3 minutes)

3. Contextualization: The teacher should then explain that the study of the physical states of matter is fundamental for understanding various natural phenomena and for the development of technologies. For example, the change in the physical state of water is essential for the occurrence of rain, snow, and ice, and also for the operation of various machines and devices, such as refrigerators and air conditioners. (2 - 3 minutes)

4. Problem situation 2: The teacher can propose a second situation: 'Why does smoke spread faster than water?' This question aims to arouse students' curiosity and prepare them for the content that will be presented about the characteristics of gases. (2 - 3 minutes)

5. Introduction of the topic: The teacher should then introduce the topic of the lesson, explaining that the physical states of matter are different forms that matter can assume, depending on temperature and pressure conditions. It should also mention that the physical states are solid, liquid, and gaseous, and that each of them has its own characteristics. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Theory - Solids, liquids, and gases (7 - 9 minutes)

   1.1. The teacher should start the theoretical part by explaining the concept of solids, liquids, and gases, their macroscopic behaviors, and their microscopic properties (the organization of particles and the forces between them).

   1.2. It should be emphasized that in solids, the particles are close to each other, organized in a three-dimensional structure, and the forces between them are strong, maintaining the shape and fixed volume.

   1.3. In liquids, the particles are close to each other, but now they have more freedom of movement. The forces between them are still strong enough to keep the volume fixed, but not enough to maintain the shape.

   1.4. In gases, the particles are very far apart, moving freely. The forces between them are very weak, allowing the gas to expand to completely fill the volume of the container.

   1.5. The teacher should use diagrams, models, and animations to illustrate these concepts, making the explanation clearer and visually appealing.

2. Practical activity - Computational simulations (8 - 10 minutes)

   2.1. The teacher should organize students into groups and provide each group with a computer.

   2.2. Each group should access a computational simulation that allows the visualization of particle movement in each physical state of matter.

   2.3. Students should carefully observe the simulations, noting the differences they perceive between the different physical states of matter.

   2.4. After observation, students should discuss in their groups the differences they noticed and how these differences can be explained by the theory presented.

3. Theory - Changes of state (5 - 7 minutes)

   3.1. The teacher should then explain the concept of changes of state of matter.

   3.2. It should be emphasized that changes of state occur when the temperature and/or pressure of a material are altered.

   3.3. It should be explained that during a change of state, the material's temperature does not change, as the energy is being used to break or form the forces between the particles.

   3.4. The teacher should present the phase diagram, which shows the temperature and pressure conditions at which each physical state of matter occurs.

   3.5. The teacher should also explain the concepts of melting point, boiling point, sublimation, condensation, and solidification, and how they relate to changes of state.

4. Practical activity - Ice experiment (5 - 7 minutes)

   4.1. To illustrate changes of state, the teacher should conduct a simple experiment with ice.

   4.2. The teacher should place an ice cube on a plate and heat the base of the plate with a lamp.

   4.3. Students should observe what happens to the ice. First, it melts, transitioning from the solid to the liquid state. Then, the water evaporates, transitioning from the liquid to the gaseous state.

   4.4. The teacher should explain that during the melting and boiling processes, the energy provided by heating is being used to break the forces between the particles and not to increase the temperature.

   4.5. After the experiment, students should discuss in their groups what they observed and how it relates to the theory presented.

Return (8 - 10 minutes)

1. Group discussion (3 - 4 minutes)

   1.1. The teacher should promote a group discussion and ask each group to present their conclusions. Each group will have a maximum of 3 minutes to share their observations and insights.

   1.2. During the presentations, the teacher should encourage students to explain their observations using the concepts presented in the lesson. This helps reinforce students' understanding of the physical states of matter and changes of state.

   1.3. The teacher should ask questions to each group, stimulating them to think critically and deepen their understanding of the topic. For example: 'Why does water evaporate more quickly when boiling than when at room temperature?'

2. Connection with theory (2 - 3 minutes)

   2.1. After the group presentations, the teacher should review the main points discussed and make the connection with the theory presented.

   2.2. The teacher should clarify any misunderstandings that may have arisen during the discussions and reinforce the most important concepts.

   2.3. The teacher should highlight how the practical activities and computational simulations helped illustrate and apply the theoretical concepts, reinforcing the importance of experimentation for learning chemistry.

3. Individual reflection (2 - 3 minutes)

   3.1. To conclude the lesson, the teacher should propose that students reflect individually on what they have learned. This can be done through questions like:

    3.1.1. 'What was the most important concept you learned today?'
    3.1.2. 'What questions have not been answered for you yet?'
   

   3.2. Students should have a minute to think about these questions. Then, the teacher can ask some students to share their answers with the class.

   3.3. The teacher should value all answers, even those that may be considered wrong or partial, as they may reveal misunderstandings that still need to be clarified.

4. Closure (2 minutes)

   4.1. The teacher should end the lesson by summarizing the main points discussed and the importance of the topic for understanding natural phenomena and the development of technologies.

   4.2. The teacher should also inform students about the content of the next lesson and any tasks that need to be prepared.

Conclusion (5 - 7 minutes)

1. Summary and Recapitulation (2 - 3 minutes) 1.1. The teacher should give a brief summary of the main points covered in the lesson, reaffirming the concepts of solid, liquid, and gaseous, and how the molecular structure and forces between particles relate to the different physical states of matter. 1.2. The changes of state of matter (melting, solidification, vaporization, condensation, and sublimation) should be recalled and how they occur when temperature and/or pressure are altered. 1.3. The teacher should reinforce the skills developed during the lesson, such as observation, experimentation, and critical thinking.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes) 2.1. The teacher should highlight how the lesson connected theory, practice, and applications. 2.2. It should be emphasized how practical activities, such as computational simulation and the ice experiment, helped illustrate and apply theoretical concepts. 2.3. The teacher should mention again the practical applications of the physical states of matter, such as the occurrence of natural phenomena and the operation of technologies.

3. Additional Materials (1 - 2 minutes) 3.1. The teacher should suggest additional materials for students who wish to deepen their knowledge on the topic. 3.2. These materials may include websites, videos, books, and experiments that students can perform at home. 3.3. For example, the teacher may suggest reading chapters from chemistry textbooks, watching explanatory videos on YouTube, engaging in interactive activities on educational websites, and conducting simple experiments with materials available at home.

4. Relevance of the Topic (1 minute) 4.1. To conclude the lesson, the teacher should emphasize the importance of the topic for students' daily lives. 4.2. It should be highlighted how understanding the physical states of matter is crucial for understanding natural phenomena, such as the formation of rain, snow, and ice, and for the operation of various technologies present in our daily lives, such as refrigerators, air conditioners, and stoves. 4.3. The teacher should also emphasize that knowledge about the physical states of matter is fundamental for the study of various areas of science and technology, such as physics, engineering, biology, medicine, and pharmacy.