Objectives (5 - 7 minutes)

1. Understand Snell's Law: The teacher should guide the students to fully understand Snell's Law and how it applies to different situations. This includes the ability to calculate refraction angles and predict the behavior of light as it passes from one medium to another.

2. Apply Snell's Law to real problems: After understanding the law, students should be able to apply it to solve practical problems. This may include determining the refraction angle in different materials or predicting the path of light in various configurations.

3. Relate Snell's Law to the real world: The teacher should help students see the relevance of Snell's Law in their daily lives. This can be done through practical examples, such as explaining how sunglasses work or why light seems to bend when passing from one medium to another.

   Secondary objectives:

   • Promote group discussion: The teacher should encourage active student participation, promoting group discussion to deepen the understanding of the subject.

   • Stimulate critical thinking: The teacher should encourage students to think critically about the application of Snell's Law and how it relates to other optics concepts.

Introduction (10 - 15 minutes)

1. Review of previous content (3 - 5 minutes): The teacher begins the class with a quick review of geometric optics concepts previously studied, such as light reflection, refractive index, and the law of reflection. This review is essential to establish the necessary foundation for understanding Snell's Law.

2. Problem situations (3 - 5 minutes): Next, the teacher presents two situations that pique students' curiosity and will be resolved throughout the class. For example, the teacher might ask why we see a "broken" pencil when it is partially submerged in water, or why a stick appears to "bend" when placed inside a glass of water.

3. Contextualization (2 - 3 minutes): The teacher then contextualizes the importance of Snell's Law, explaining that it is fundamental to understanding optical phenomena that occur in our daily lives, such as the formation of rainbows, the functioning of lenses and cameras, among others. Additionally, the teacher can mention some practical applications of the law, such as in the construction of prisms and determining the depth of a body of water from the refraction angle.

4. Introduction to the topic (2 - 3 minutes): To introduce the topic attractively, the teacher can tell the story of Snell, the scientist who discovered the law that bears his name. Additionally, they can present some curiosities, such as the fact that Snell's Law was one of the first physical laws to be formulated mathematically. Another interesting curiosity is that Snell's Law is one of the reasons why light seems to "break" when passing from one medium to another, as in the case of the pencil in water.

Development (20 - 25 minutes)

1. Activity "Experimenting with Snell's Law" (10 - 12 minutes): The teacher should divide the class into groups of five and provide each group with a set of materials: a transparent container with water, a ruler, a marker, and a popsicle stick. The activity consists of:

   • Each group should fill the container with water and mark the water level with the marker.
   • Next, a group member should hold the popsicle stick vertically at the 1 cm mark on the ruler, outside the container.
   • Another group member should observe through the side of the container, align the popsicle stick with the marker on the ruler, and mark the position of the top of the stick on the container.
   • Students should repeat the process with the stick inside the container, observing through the side.
   • Students should measure the distance between the two marks on the container and the height of the stick outside the container.
   • Students should repeat the activity, varying the angle of inclination of the stick.

   The teacher should circulate around the room, guiding students as needed and encouraging discussion among group members. Later, the teacher should guide students to realize that the activity demonstrates the change in light direction (refraction) when it passes from one medium to another (in this case, from air to water). The data collected by the students can be used to calculate the refractive index of water, which is a direct application of Snell's Law.

2. Activity "The mystery of the broken pencil" (10 - 12 minutes): Still in groups, students will receive a pencil and a transparent glass with water. The activity consists of:

   • A group member should hold the pencil vertically, so that the bottom part of the pencil is immersed in water and the top part is outside the glass.
   • Another group member should observe the pencil from a point of view where it appears "broken".
   • Students should repeat the activity, varying the viewing angle.

   The teacher should circulate around the room, observing the groups' activities and guiding them as needed. At the end of the activity, the teacher should lead a discussion with the class, using students' observations to explain the phenomenon of refraction and the application of Snell's Law.

3. Activity "Refraction Treasure Hunt" (5 - 7 minutes): To conclude the Development stage, the teacher should propose a playful activity.

   • The teacher should hide objects of different colors in various points of the room. Each object should be in a transparent container with a liquid of different refractive index (water, oil, air, etc.).
   • Students, still in their groups, should receive a list with the objects and the corresponding liquids. They should identify the objects and fill out the list correctly.
   • The goal is for students to practically perceive how light refraction varies according to the medium in which it propagates.

At the end of the Development, students will have had the opportunity to explore Snell's Law in a playful and practical way, understanding its application in real situations and consolidating their learning.

Return (8 - 10 minutes)

1. Group discussion (3 - 4 minutes): The teacher should gather all students and promote a group discussion about the solutions or conclusions found by each group during the activities. This allows students to share their discoveries, clarify doubts, and learn from each other. The teacher should encourage students to explain their reasoning and listen attentively to their peers' arguments.

2. Connection with theory (2 - 3 minutes): The teacher should then bridge the gap between practical activities and the studied theory. They should recall the concepts of Snell's Law and how they apply to the situations presented in the activities. The teacher can, for example, ask students how the "Mystery of the Broken Pencil" activity relates to the law, or how the "Refraction Treasure Hunt" activity demonstrates the variation of the refractive index in different media.

3. Individual reflection (1 - 2 minutes): Next, the teacher should propose that students individually reflect on what they learned in the class. They can ask questions like:

   • What was the most important concept learned today?
   • What questions remain unanswered?
   • How can you apply what you learned today in everyday situations?

4. Feedback (1 - 2 minutes): The teacher should collect students' reflections, either through a brief classroom discussion or an online questionnaire. This feedback is valuable for the teacher to assess the effectiveness of the lesson and plan the next teaching steps. Additionally, it is an opportunity for the teacher to clarify any remaining doubts and reinforce the most important concepts.

5. Homework (1 minute): To consolidate learning, the teacher can propose a homework assignment involving the application of Snell's Law in everyday situations. For example, students can be challenged to explain why sunlight seems to bend when passing through a window, or why fish appear to be in a different place than they actually are when observed from outside the water.

At the end of the Return, students will have had the opportunity to reflect on what they learned, clarify doubts, and prepare for the next class. Additionally, the teacher will have received valuable feedback to improve their teaching practices.

Conclusion (5 - 7 minutes)

1. Summary and Recap (1 - 2 minutes): The teacher should begin the Conclusion by recapping the main points covered in the class. This includes the definition of Snell's Law, how it applies to light refraction, and how to calculate the refraction angle. The teacher can use a diagram on the board or presentation slides to visually reinforce the concepts.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes): Next, the teacher should reinforce how the class connected theory (Snell's Law) with practice (activities "Experimenting with Snell's Law", "The mystery of the broken pencil", and "Refraction Treasure Hunt") and real applications (real-world examples, such as the functioning of sunglasses and the formation of rainbows). The teacher can highlight how understanding the theory allowed students to solve practical problems and better understand everyday phenomena.

3. Extra Materials (1 - 2 minutes): The teacher should suggest extra materials for students who want to deepen their knowledge of Snell's Law. This can include additional readings, explanatory videos, interactive websites, etc. The teacher can share the links to these materials through an online platform, such as an LMS (Learning Management System) or a class messaging group. Additionally, the teacher can recommend that students practice more problem-solving related to Snell's Law to consolidate their learning.

4. Importance of the Subject (1 - 2 minutes): Finally, the teacher should reinforce the importance of Snell's Law in everyday life. They can refer to more practical examples, such as the use of lenses in glasses and cameras, the formation of images in curved mirrors, etc. The teacher can also emphasize how understanding Snell's Law can contribute to interpreting the world around us and solving practical problems.

At the end of the Conclusion, students should have consolidated the knowledge acquired during the class, understood the relevance of the subject, and felt motivated to explore more about Snell's Law.