Objectives (5 - 7 minutes)

1. Introducing the concept of aldehydes: The teacher should explain what aldehydes are, what their characteristics are, and how they differ from other types of organic compounds.

2. Teaching the nomenclature of aldehydes: The teacher should present the rules for naming aldehydes, emphasizing the importance of recognizing and correctly using the prefixes and suffixes that indicate the presence of aldehydes in a molecule.

3. Providing practice in aldehyde nomenclature: The teacher should offer practice exercises so that students can apply what they have learned about aldehyde nomenclature. This will help consolidate knowledge and develop problem-solving skills.

Secondary Objectives:

• Stimulating critical thinking: During the lesson, the teacher should encourage students to think critically about the concepts presented. This can be done through challenging questions or group discussions.

• Promoting active participation: The teacher should create an interactive classroom environment, encouraging students to actively participate in discussions and activities. This can be done through open-ended questions, debates, or group activities.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher should start the lesson with a brief review of the hydrocarbons and organic functions concepts already studied. This is essential for students to understand the structure and characteristics of aldehydes, the main focus of the lesson. (3 - 5 minutes)

2. Presentation of problem situations: The teacher should propose two situations that arouse students' interest and motivate them to learn about aldehyde nomenclature. One possibility is to present the chemical structure of an aldehyde without revealing its name and challenge students to discover its nomenclature. Another situation could be the presentation of a real problem, such as identifying an aldehyde in a commonly used chemical substance. (5 - 7 minutes)

3. Contextualization of the topic's importance: The teacher should explain the importance of aldehyde nomenclature in the field of chemistry, emphasizing that the correct identification and naming of these compounds is essential for understanding and applying various chemical processes, from the synthesis of medicines and plastics to the production of food and perfumes. Additionally, the teacher can emphasize that aldehyde nomenclature is a valued skill in various careers, including chemistry, pharmacy, biology, and medicine. (2 - 3 minutes)

4. Introduction of the topic with curiosities: To spark students' interest, the teacher can share some curiosities about aldehydes. For example, they can mention that formaldehyde, a common substance in laboratories and beauty salons, is an aldehyde. Additionally, the teacher can comment that aldehyde nomenclature was developed throughout the history of chemistry as part of efforts to organize and categorize the millions of existing organic compounds. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Theory - Aldehydes Concept (5 - 7 minutes): The teacher should start the theoretical part of the lesson by explaining what aldehydes are. It should be emphasized that aldehydes are organic compounds that have the functional group carbonyl, represented by -CHO. The teacher should show the difference between aldehydes and other compounds with carbonyl, such as ketones, carboxylic acids, and esters. Additionally, it may be useful to explain that aldehydes are often found in fruits and perfumes, and that many have a characteristic odor.

2. Theory - Aldehyde Nomenclature (5 - 7 minutes): The teacher should introduce the rules of aldehyde nomenclature. It should be explained that the official nomenclature of aldehydes follows the rule that the suffix "al" is added to the name of the corresponding hydrocarbon. The teacher should give examples, such as formaldehyde (from methane), acetaldehyde (from ethane), and propionaldehyde (from propane). Additionally, the teacher should remind students that the carbon of the carbonyl is always numbered as 1.

3. Theory - Aldehyde Nomenclature Practice (5 - 7 minutes): The teacher should propose some examples of aldehydes and challenge students to name them. It is important for the teacher to explain each step of the naming process, clarifying doubts and correcting errors. The teacher should focus on aldehydes with longer and more complex carbon chains so that students can practice numbering the carbons.

4. Practice - Aldehyde Nomenclature Exercises (5 - 7 minutes): The teacher should provide students with a list of aldehyde nomenclature exercises to be solved individually or in groups. It is important for the teacher to circulate around the classroom, assisting students and clarifying doubts. After solving the exercises, the teacher should correct them together with the class, explaining step by step the correct nomenclature of each aldehyde.

5. Theory Review - Group Discussion (2 - 3 minutes): To conclude the Development stage, the teacher should propose a group discussion on aldehyde nomenclature. The teacher can ask questions that encourage students to think critically about the subject, such as "Why is aldehyde nomenclature important in chemistry?" or "What challenges did you encounter when naming the aldehydes?".

Return (8 - 10 minutes)

1. Review and reflection (3 - 4 minutes): The teacher should encourage students to reflect on what was learned during the lesson. This can be done by asking each student or group to share an answer to the following questions:

   • What was the most important concept learned today?
   • What questions have not been answered yet?
   • How does aldehyde nomenclature apply to everyday situations?

2. Connection to practice (3 - 4 minutes): Next, the teacher should help students connect the theory learned with practice. This can be done by showing examples of how aldehyde nomenclature is used in various areas, such as the pharmaceutical industry, food production, forensic chemistry, among others. Additionally, the teacher can propose an application exercise where students will have to name aldehydes found in everyday products, such as perfumes, foods, and medicines.

3. Final reflection (2 - 3 minutes): Finally, the teacher should propose that students silently reflect for a minute on answers to questions such as:

   • What was the most important concept learned today?
   • What questions have not been answered yet?

4. Teacher feedback (1 minute): After the reflection, the teacher should conclude the lesson by giving overall feedback on the class performance. They can highlight strengths, areas that need more practice, and common doubts. Additionally, the teacher should encourage students to review the lesson content at home and to seek the teacher or classmates to clarify any doubts they may have.

5. Sharing of extra materials (1 minute): Finally, the teacher should share additional study materials with students, such as videos, websites, books, and online exercises, so they can review the lesson content and prepare for the next one.

Conclusion (3 - 5 minutes)

1. Summary of Contents (1 - 2 minutes): The teacher should recap the main points covered during the lesson. This includes the definition of aldehydes, their characteristics, the structure of the carbonyl functional group, and the nomenclature rules. The teacher can do this interactively by asking students to recall each of these points.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes): The teacher should reinforce how the lesson connected theory, practice, and applications. For example, by naming the aldehydes, students not only learned about nomenclature but also about the structure of aldehydes and carbon numbering. Additionally, the teacher should remind students how aldehyde nomenclature is applied in various areas, from everyday chemistry to industry and scientific research.

3. Suggestions for Study Materials (1 minute): The teacher should suggest some study materials for students who wish to deepen their understanding of aldehyde nomenclature. This may include organic chemistry books, online chemistry sites, educational videos, and online nomenclature exercises. The teacher should emphasize the importance of reviewing the material at home and completing the exercises to improve their nomenclature skills.

4. Importance of the Topic for Everyday Life (1 minute): Finally, the teacher should reinforce the importance of the topic for everyday life. This can be done by reminding students that aldehydes are found in many products we use daily, such as perfumes, foods, and medicines. Additionally, the teacher can mention that the ability to name aldehydes is valued in various careers, including chemistry, pharmacy, biology, and medicine. The teacher should encourage students to continue exploring the chemistry around them and to seek opportunities to apply what they have learned in the lesson.