Objectives (5 - 7 minutes)

1. Understand and apply the resistivity formula: Students should understand how resistivity is calculated and how it affects the resistance of a material. They should be able to apply this formula to practical problems.

2. Apply the 2nd Ohm's Law: Students should be able to use the 2nd Ohm's Law to solve problems involving current, resistance, and voltage. They should understand how changes in one of these components affect the others and become familiar with the formula V = I x R.

3. Relate resistivity and 2nd Ohm's Law: Students should be able to relate the resistivity of a material to the 2nd Ohm's Law. They should understand how the resistivity of a material influences the circuit's resistance and, consequently, the current and voltage.

Secondary Objectives:

• Develop problem-solving skills: In addition to understanding the theory, students should be able to apply these concepts to solve practical problems. This includes the ability to identify relevant variables and use the appropriate formulas.
• Stimulate critical thinking: Throughout the lesson, students should be encouraged to question and think critically about the concepts presented. They should be able to articulate their doubts and discuss different approaches to problem-solving.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should start the lesson by reviewing basic concepts of electricity, such as the definition of current, voltage, and resistance. It is also important to review the 1st Ohm's Law and how it relates to resistance. This review can be done through questions directed at the students to assess the level of previous understanding and to stimulate active participation from the beginning of the lesson.

2. Problem situation: The teacher should then present two problem situations that will guide the Theory Development. The first one could be: 'Imagine you have a circuit with a copper wire and another with an aluminum wire. If the voltage and resistance are the same in both circuits, will the current be the same? Why?'. The second problem situation could be: 'Imagine you have a circuit with a copper wire and another with an aluminum wire. If the current is the same in both circuits, will the voltage be the same? Why?'.

3. Contextualization: The teacher should then contextualize the importance of studying resistivity and the 2nd Ohm's Law, explaining how these concepts are essential for the operation of various electrical devices we use in our daily lives, such as light bulbs, refrigerators, computers, among others. In addition, the importance of these concepts in areas such as electrical engineering and materials physics can be mentioned.

4. Introduction to the topic: To spark students' interest, the teacher can share some curiosities or practical applications related to the topic. For example, it can be mentioned that copper is often used in electrical wires due to its low resistivity. Additionally, it can be mentioned that the resistivity of certain materials, such as silicon, can be altered through doping processes, which is crucial for the operation of electronic devices like transistors and microchips.

   1. Curiosity 1: 'Did you know that copper is often used in electrical wires due to its low resistivity? This means that current can flow more easily through copper than through other metals, making copper an excellent conductor of electricity.'
   2. Curiosity 2: 'And how about this? The resistivity of certain materials, such as silicon, can be altered through doping processes. This is essential for the operation of electronic devices like transistors and microchips, which are the basis of many modern technologies.'

Development (20 - 25 minutes)

1. 'Play-Doh Circuit' Activity (10 - 12 minutes)

   • Description: In this activity, students will simulate an electrical circuit using Play-Doh of different colors, each representing a material with a certain resistivity. The teacher will provide batteries, metal wires of different types (copper, aluminum, iron, etc.), voltmeters, and ammeters.
   • Step by step:
     1. Students, divided into groups, will receive the materials.
     2. Each group should assemble a circuit with a battery, a metal wire, a voltmeter (to measure voltage), and an ammeter (to measure current).
     3. Students will record the voltage and current in the circuit and then replace the metal wire with another of a different material.
     4. They will repeat this process several times, noting the voltage and current values for each metal wire.
     5. At the end of the activity, students should have a table with the voltage and current values for each metal wire, allowing them to analyze how resistivity affects voltage and current.
   • Objective: The objective of this activity is to allow students to observe practically how the resistivity of a material affects voltage and current in a circuit.

2. 'Resistivity and Resistance' Activity (10 - 12 minutes)

   • Description: In this activity, students will work with the resistivity formula and use the 2nd Ohm's Law to calculate the resistance of different materials. The teacher will provide resistors of different resistances, wires of different materials, and a multimeter.
   • Step by step:
     1. Students, still divided into groups, will receive the materials.
     2. Each group should measure the resistance of a metal wire using the multimeter and record the value.
     3. Then, they should use the resistivity formula to calculate the resistance that the wire should have, considering the dimensions of the wire and the material's resistivity.
     4. They will compare this value with the measured resistance and discuss possible sources of error.
     5. Students will repeat this process for several wires of different materials, allowing them to explore how resistivity affects resistance.
   • Objective: The objective of this activity is to allow students to apply the resistivity formula and observe how it relates to the measured resistance.

3. Group Discussion (5 - 7 minutes)

   • Description: After the conclusion of the activities, the teacher will promote a group discussion where students will have the opportunity to share their observations and conclusions. The teacher will guide the discussion, asking questions to stimulate critical thinking and ensure that all concepts were understood.
   • Step by step:
     1. The teacher will ask each group to share their observations and conclusions from the activities.
     2. The teacher will ask questions to stimulate reflection, such as 'Why is the current higher in a copper wire than in an aluminum wire, if the voltage and resistance are the same?' or 'How is the resistance of a metal wire affected by its resistivity?'.
     3. The teacher will summarize the main conclusions of the discussion and clarify any remaining doubts.
   • Objective: The objective of this discussion is to consolidate learning, clarify any doubts, and stimulate critical thinking.

Return (8 - 10 minutes)

1. Group Discussion - Sharing Conclusions (3 - 4 minutes)

   • Description: The teacher will ask each group to share their findings and conclusions from the 'Play-Doh Circuit' and 'Resistivity and Resistance' activities. Each group will have a maximum of 2 minutes to present. The teacher should ensure that all students have the opportunity to speak, encouraging everyone's participation.
   • Step by step:
     1. The teacher will ask each group to share their main findings and conclusions from the activities.
     2. Each group will have up to 2 minutes to make their presentation.
     3. During the presentations, the teacher should pay attention to identify and highlight the most important points and to verify if the students are correctly understanding the concepts.
   • Objective: The objective of this discussion is to allow students to share their findings, reinforce what they have learned, and learn from others' experiences.

2. Connection with Theory (2 - 3 minutes)

   • Description: After the presentations, the teacher will revisit the theoretical concepts discussed in the lesson's Introduction and will connect these concepts with the students' findings and conclusions. The teacher should emphasize how the practical activities confirmed the theory and how the theory helps explain the results of the activities.
   • Step by step:
     1. The teacher will revisit the theoretical concepts of resistivity and the 2nd Ohm's Law.
     2. The teacher will explain how these concepts connect with the students' findings and conclusions, using concrete examples from the activities.
   • Objective: The objective of this stage is to reinforce students' understanding of the theoretical concepts and show the relevance and applicability of these concepts.

3. Final Reflection (2 - 3 minutes)

   • Description: To conclude the lesson, the teacher will propose that students reflect for a minute on the following questions: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?'. Students will have a minute to think and then can share their answers if they wish.
   • Step by step:
     1. The teacher will propose the reflection questions and give students a minute to think about their answers.
     2. Students who wish to can share their answers with the class.
     3. The teacher will thank the students for their participation and end the lesson.
   • Objective: The objective of this final reflection is to allow students to consolidate what they have learned, identify possible doubts, and prepare for the next lesson. Additionally, this stage also helps the teacher assess the effectiveness of the lesson and identify possible areas for improvement for future lessons.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes)

   • Description: The teacher should give a brief summary of the main points covered in the lesson, reinforcing the concepts of resistivity and the application of the 2nd Ohm's Law. The objective is to remind students of what was learned and provide an overview of the topics that will be further explored in the upcoming lessons.
   • Step by step:
     1. The teacher should summarize the concepts of resistivity and the 2nd Ohm's Law, reminding students of the importance of these concepts for understanding the behavior of electricity in different materials.
     2. The teacher should also review the formulas and procedures used to solve the practical problems discussed during the lesson.
   • Objective: The objective of this summary is to consolidate students' learning, reinforcing the concepts and skills that were developed during the lesson.

2. Connection between Theory and Practice (1 - 2 minutes)

   • Description: The teacher should explain how the lesson connected theory with practice, showing how the activities carried out illustrated the theoretical concepts presented. This may include recalling experiments, simulations, or other practical activities carried out during the lesson, as well as discussing how these activities helped to better understand the theoretical concepts.
   • Step by step:
     1. The teacher should recall the practical activities carried out during the lesson and how they illustrated the theoretical concepts.
     2. The teacher should also recall the discussions and reflections that arose from these activities, highlighting how they helped to better understand the theoretical concepts.
   • Objective: The objective of this connection is to show students the relevance and applicability of the theoretical concepts, encouraging them to make connections between theory and practice in their own learning.

3. Extra Materials (1 - 2 minutes)

   • Description: The teacher should suggest extra materials for students who wish to deepen their knowledge on the topic. These may include books, articles, online videos, educational websites, among others. The teacher should briefly explain what each material covers and how it can complement what was learned during the lesson.
   • Step by step:
     1. The teacher should present the extra materials, briefly explaining what each of them covers.
     2. The teacher should also provide guidance on how students can access these materials, whether in the school library, online, or from other sources.
   • Objective: The objective of this suggestion of materials is to provide students with the opportunity to explore the topic in greater depth, according to their own interests and learning pace.

4. Relevance of the Topic (1 minute)

   • Description: To conclude the lesson, the teacher should emphasize the importance of the topic studied for daily life and for other disciplines. This may include explaining how understanding resistivity and the 2nd Ohm's Law is crucial for the operation of many electronic devices we use daily, as well as for fields like electrical engineering and materials physics.
   • Step by step:
     1. The teacher should briefly explain how resistivity and the 2nd Ohm's Law are applied in everyday situations.
     2. The teacher should also mention how these concepts are important in other disciplines and in careers related to electricity and electronics.
   • Objective: The objective of this explanation is to show students that what they are learning in the lesson has practical applications and is relevant to their lives and the world around them.