Objectives (5 - 10 minutes)

1. Understand the property of light and its ability to pass through different materials, such as transparent, translucent, and opaque materials.
2. Identify and differentiate the different types of objects according to the passage of light (transparent, translucent, opaque).
3. Promote practical experimentation to observe the effect of the passage of light through different objects, encouraging curiosity and critical thinking.

The objectives stage sets the basis for understanding the topic and prepares students for the practical activities to come. At this moment, the teacher should clearly explain the three objectives of the class, ensuring that all students understand what they will be able to do at the end of the class.

The teacher can use everyday examples to illustrate the concepts, such as the use of sunglasses (opaque) that block sunlight, the glass window (transparent) that lets light pass through, and the wax paper (translucent) that allows light to pass through but does not clearly show the other side.

This stage is vital for the success of the class, as it establishes the foundation for understanding and subsequent practice.

Introduction (10 - 15 minutes)

1. Review: The teacher should start the class by briefly reviewing the concepts of light that have already been studied previously, such as the origin of light (sun, lamps, candles, etc.) and the importance of light for vision.

2. Problem situations:

   • The teacher can propose the following situation: "Imagine that you are in a dark room and turn on a flashlight. What will happen if you place different types of objects in front of the flashlight, such as a glass cup, a piece of paper or a book?"
   • Another problem situation could be: "If you are looking at an object through a glass window, what will happen if you place a piece of paper or a cloth on the window?"

3. Contextualization: The teacher can mention the importance of the passage of light through objects in real situations. For example, the choice of materials for curtains (translucent) that allow partial light to pass through without revealing the interior, or the importance of sunglasses (opaque) that block UV light to protect our eyes.

4. Introduction to the topic:

   • The teacher can start by introducing the topic in an interesting way, saying: "Did you know that light can pass through some objects and not others? And that there are objects that let light pass through, but we can't see clearly through them? Today, we're going to learn about this and do some cool experiments!".
   • As a curiosity, the teacher can mention that animals see the world differently than we do. For example, some snakes can "see" infrared light, which is invisible to us, and birds can see ultraviolet light.

The introduction is an essential step to arouse students' interest, establish the relevance of the topic and prepare them for the concepts and activities to come. The teacher should ensure that all students understand the problem situations and are ready to explore the answers during the class.

Development (15 – 20 minutes)

During this stage, three fun practical activities are proposed that the teacher can choose to do with the class. Each activity provides an opportunity for students to explore the concept of light passing through different materials. This phase takes approximately fifteen to twenty minutes.

Activity 1: "Transparent, Translucent and Opaque Objects Hunt"

1. Divide the class into small groups and provide each group with a working flashlight.

2. The teacher should clearly explain to the students that transparent objects allow light to pass through completely, opaque objects do not allow light to pass through, and translucent objects allow light to pass through, but in a diffused way, not allowing us to see clearly through them.

3. The groups will be challenged to find examples of each type of object within the classroom using their flashlights.

4. After the "hunt", each group will present the objects they found and explain why they categorized them as transparent, translucent or opaque.

Activity 2: "Shadow Theater"

1. The teacher divides the class into groups and provides each group with a sheet of cardboard, a flashlight and several different objects (toys, writing tools, building blocks, etc.).

2. Each group is given the task of creating a "shadow theater", positioning the objects between the flashlight and the cardboard in order to project different shadows.

3. Students observe how different objects (opaque, translucent and transparent) affect the light and the projected shadow.

Activity 3: "Light Saber"

1. Each student will receive an empty straw and a small flashlight.
2. Students place the flashlight inside the straw and observe how the light passes through it (or not).
3. Next, students cover one side of the straw with different materials (paper, plastic, aluminum foil, etc.) and experiment how the passage of light is affected by each material.
4. Students will share their observations with the class and the teacher will guide them to conclude which materials are opaque, translucent or transparent.

The teacher should monitor the development of the activities in all groups, providing guidance when necessary and ensuring that all students are involved and understanding the concept. The conclusion and discussion at the end of each activity are essential to reinforce learning and to correct any misconceptions.

Feedback (10 - 15 minutes)

1. Group Discussion: After the completion of the activities, the teacher should gather all the students in a large circle to promote a group discussion. Each group will have the opportunity to present their findings and conclusions. The teacher should encourage students to ask questions and make comments on their classmates' presentations, fostering a collaborative learning environment.

2. Connection with Theory: At this moment, the teacher should revisit the theoretical concepts addressed at the beginning of the class and connect them with the practical experiences of the activities carried out. For example, "Remember when we talked about transparent, translucent and opaque objects? Now that we've done the experiments, can you give examples of each of these types of objects?" Thus, the teacher can check the students' understanding and correct any misconceptions.

3. Individual Reflection: To close the class, the teacher should propose a moment of individual reflection. Each student will have a minute to think about what they have learned in the class. The teacher can guide the reflection with two simple questions:

   • "What was the most interesting thing you learned today about the passage of light through objects?"
   • "Can you think of an example from your daily life that demonstrates what we learned about the passage of light through objects?"

This feedback moment is essential to consolidate learning, assess students' understanding and encourage self-reflection. The teacher should ensure that all students have the opportunity to express their ideas and feelings, fostering an environment of mutual respect and support. The feedback stage takes approximately ten to fifteen minutes.

Conclusion (5 - 10 minutes)

1. Summary and Recapitulation: The teacher should summarize the class, reiterating the fundamental concepts learned by the students. He or she can recall the definition of transparent, translucent and opaque objects, and how light behaves when interacting with each of them. The teacher can ask students to define these terms in their own words, to assess their understanding of the concepts.

2. Connection between Theory and Practice: The teacher should highlight how the class combined theory and practice to facilitate the students' understanding. He or she can use as an example one of the experiments carried out and explain how it illustrated the theory discussed at the beginning of the class. This connection between theory and practice will reinforce the concept and show students how theoretical knowledge can be applied in practice.

3. Extra Materials: The teacher can suggest some extra materials for students who wish to deepen their knowledge on the subject. These materials could include science books, educational websites, YouTube videos and interactive learning apps. The teacher can also assign a small research project to the students, where they will have to investigate more about the topic and present their findings in the next class.

4. Importance of the Subject: Finally, the teacher should emphasize the importance of the concepts learned to the daily lives of the students. He or she can cite examples of everyday situations in which the passage of light through different materials is relevant, such as the use of curtains to block sunlight, the choice of sunglasses to protect the eyes, and the importance of windows being made of transparent glass.

The conclusion is an essential stage of the lesson plan, as it allows the teacher to review the concepts learned, assess the students' understanding, suggest resources for further learning and highlight the relevance of the topic to everyday life. This stage takes approximately five to ten minutes.