Objectives (5 - 7 minutes)

1. Understanding the concept of mixtures and their separation: Students should be able to identify what a mixture is and why it is important to be able to separate them. They should understand that mixtures can be separated into their original components, either through physical or chemical methods.

2. Knowledge of the main methods of separation of mixtures: Students should be able to identify and describe the main methods of separation of mixtures, including filtration, decantation, evaporation, distillation, and chromatography.

3. Ability to apply the acquired knowledge: Students should be able to apply the acquired knowledge to solve practical problems. For example, they should be able to determine the most appropriate separation method for a given mixture.

Secondary Objectives

1. Promote teamwork skills: During practical activities, students will be encouraged to work in groups. This will help develop their collaboration and communication skills.

2. Stimulate critical thinking and problem-solving: When facing various examples of mixtures to be separated, students will be challenged to think critically and apply their problem-solving skills.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should start the lesson by briefly reviewing the concepts of matter and pure substances, which were studied in previous classes. This review can be done interactively, with questions and answers to students to check their understanding of the subject. (3 - 5 minutes)

2. Presentation of problem situations: The teacher should propose two situations involving the separation of mixtures to instigate the curiosity of the students and prepare them for the topic of the lesson. For example, he can ask: 'How would you separate salt from seawater?' or 'How would we separate iron from a batch of steel screws?'. These questions should be discussed in groups, but do not need to be solved at this time. (3 - 5 minutes)

3. Contextualization of the importance of the subject: The teacher should then contextualize the importance of the separation of mixtures, explaining how this concept is applied in various everyday situations and in various industries. For example, he can mention the importance of separating recyclable materials, separating components in industrial processes, or even separating substances in laboratory experiments. (2 - 3 minutes)

4. Introduction of the topic with curiosities: To arouse the students' interest, the teacher can share some curiosities related to the subject. For example, he can mention that the separation of mixtures is one of the oldest research areas in chemistry and that many of the methods we use today were developed centuries ago. Another curiosity is that the separation of mixtures is a fundamental topic in astrochemistry, as astronomers use separation methods to analyze the composition of distant stars and planets. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Activity 'Discovering Methods' (10 - 12 minutes)

   • Description: For this activity, the teacher should prepare five workstations, each with a different mixture and all the materials necessary for the separation of the mixture. The mixtures may include: saltwater, sand and iron filings, paint and water, alcohol and water, and coffee powder and water.
   • Procedure: Divide the class into groups of five and ask each group to go to a station. Explain that they will have to discover which is the most appropriate method to separate the mixture at the station and then follow the steps to perform the separation. Give students about 2 minutes to discuss and decide which method to use. Then allow them to work on the separation of the mixture, ensuring that all group members are involved and understand the process. After completion, students should clean the station and move on to the next one. Repeat the procedure until all groups have gone through all stations.
   • Objective: This activity aims to allow students to apply the acquired knowledge in a practical way and develop their problem-solving and teamwork skills.

2. Activity 'Separating for Recycling' (10 - 12 minutes)

   • Description: In this activity, the teacher should provide students with several trash cans containing different types of waste (plastic, paper, metal, glass, etc.). Students, in their groups, should examine the contents of the cans and determine which separation methods would be most appropriate to separate the waste into its original components.
   • Procedure: Divide the class into groups of five and give each group several trash cans. Explain that they should examine the contents of the cans and identify the different types of waste present. Then, they should discuss and determine which separation methods would be most appropriate to separate the different types of waste. For example, they may suggest recycling paper and plastic, separating metal from glass using a magnet, etc. Students should present their proposals to the class and discuss the reasons behind their choices.
   • Objective: This activity aims to have students apply the acquired knowledge to a real-world situation, the separation of waste for recycling. Additionally, it promotes students' awareness of the importance of recycling and proper waste management.

3. Discussion and Reflection (5 - 7 minutes)

   • Description: After the completion of the activities, the teacher should promote a classroom discussion about the solutions proposed by the groups and the difficulties encountered. In addition, students should be encouraged to make connections between the activities and the real world.
   • Procedure: The teacher should start the discussion by asking students about their experiences during the activities. He should ask about the separation methods chosen, why they were chosen, and how they worked. The teacher should also ask about the difficulties encountered and how they were overcome. Finally, the teacher should ask students to reflect on the importance of the separation of mixtures in their daily lives and in society in general.
   • Objective: This discussion aims to consolidate the knowledge acquired by students, clarify any remaining doubts, and allow students to reflect on the practical application of what they have learned.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes)

   • Description: The teacher should gather the students in a large circle and start a group discussion. Each group will have 2 minutes to share their solutions or conclusions from the 'Discovering Methods' and 'Separating for Recycling' activities. During this discussion, students will be encouraged to explain the methods they chose, why they thought they would be effective, and what they learned from the experience.
   • Procedure: The teacher should give each group the opportunity to share their findings. While one group is speaking, the others should listen attentively and, if they have something to add, they should wait for their turn to speak. The teacher should moderate the discussion, ensuring that all groups have the chance to speak and that the discussion remains focused on the topic.
   • Objective: This group discussion allows students to share their experiences and learn from each other. Additionally, it helps reinforce what was learned during the practical activities.

2. Connection with Theory (2 - 3 minutes)

   • Description: After the group discussion, the teacher should give a brief review of the theoretical concepts presented at the beginning of the lesson. He should then connect these concepts with the solutions or conclusions that the groups shared. For example, he can say: 'Remember when we talked about evaporation? Group X used this method to separate the paint from the water.'
   • Procedure: The teacher should review the theoretical concepts clearly and concisely, and then make direct connections with the practical activities. He should ensure that all students understand how the theory applies to the practical situations discussed.
   • Objective: This step helps reinforce the connection between theory and practice, and show students how theoretical knowledge can be applied to solve real-world problems.

3. Individual Reflection (2 - 3 minutes)

   • Description: To conclude the lesson, the teacher should propose that students reflect individually on what they have learned. He should ask some questions to guide this reflection, such as: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?'.
   • Procedure: The teacher should give students a minute to think about the questions and then ask some volunteers to share their answers with the class. The teacher should listen carefully to the students' responses and, if there are unanswered questions, he should note them to be addressed in the next lesson.
   • Objective: This final reflection helps consolidate what was learned during the lesson and identify any areas that have not been understood yet. Additionally, it provides the teacher with valuable feedback on the effectiveness of his instruction and on any concepts that may need further review.

Conclusion (5 - 7 minutes)

1. Recap of key points (2 - 3 minutes)

   • Description: The teacher should give a brief summary of the key points covered during the lesson, reiterating the definition of mixtures, the discussed separation methods, and the importance of the separation of mixtures in everyday life and science.
   • Procedure: The teacher should review the main concepts, one by one, and check if the students understood each point. He can ask questions to engage students in the recap and ensure that the material has been understood.

2. Connection between theory, activities, and applications (1 - 2 minutes)

   • Description: The teacher should explain how the lesson connected theory (concepts of mixture and separation), practice (separation activities), and applications (everyday and real-world situations where the separation of mixtures is useful).
   • Procedure: The teacher should provide concrete examples of how theory was applied in the practical activities, and how these skills can be used to solve real-world problems. He should emphasize the practical value of what was learned.

3. Suggestion of additional materials (1 - 2 minutes)

   • Description: The teacher should suggest additional resources for students who wish to deepen their understanding of the topic. These resources may include reference books, educational websites, explanatory videos, and related experiments.
   • Procedure: The teacher should provide a list of resources, along with a brief description of each and the reason why it is recommended. He can also ask students to share any other useful resources they may know.

4. Importance of the topic for daily life and science (1 minute)

   • Description: Finally, the teacher should reinforce the relevance of the topic for everyday life and science. He should highlight how the ability to separate mixtures is used in a variety of contexts, from food preparation to the chemical industry and space research.
   • Procedure: The teacher should summarize the examples of applications of the topic discussed during the lesson and reinforce the importance of learning to separate mixtures. He should encourage students to apply what they have learned in their daily lives and to continue exploring the topic.