Objectives (5 - 7 minutes)

1. Understanding the Concept of Salt: Students should be able to define what a salt is, identify its properties, and recognize the importance of salts in everyday life. This includes understanding the formation of a salt from the bonding between a cation and an anion.

2. Recognition of Salt Characteristics: Students should be able to differentiate between different types of salts, such as neutral, acidic, and basic salts. This includes the ability to identify the cations and anions that make up a salt and how they influence its properties.

3. Ability to Name and Write Salt Formulas: Students should be able to correctly name and write the chemical formulas of different types of salts. This includes applying naming rules and understanding how cations and anions are represented in a chemical formula.

Secondary Objectives:

• Application of Knowledge in Practical Situations: Students should be able to apply the knowledge acquired about salts in everyday situations, such as identifying salts in food or cleaning products.

• Development of Problem-Solving Skills: Through the study of salts, students will be encouraged to develop critical thinking and problem-solving skills, which will contribute to their overall development as science students.

Introduction (10 - 15 minutes)

1. Review of Previous Concepts: The teacher should start the lesson by briefly reviewing the concepts of acids and bases, as salts are formed from the reaction between these two classes of compounds. The basic structure of an ion can also be reviewed, as salts are formed by the bonding between ions. The teacher can do this through direct questions to the students or through a quick interactive activity.

2. Problem Situations: Next, the teacher should present two problem situations to spark the students' interest. The first one could be: "Why does food taste salty when we add salt to it?" and the second: "Why is salt used to melt ice on roads in winter?" These questions should serve as a starting point for the discussion on the lesson's topic.

3. Contextualization of the Subject: The teacher should then contextualize the importance of salts in everyday life, explaining that salts play an essential role in various biological functions and are widely used in industry and agriculture. Additionally, salts are commonly used at home, in the kitchen, and for cleaning.

4. Introduction of the Topic: To introduce the topic in an engaging way, the teacher can share some curiosities about salts. For example, they can mention that table salt, or sodium chloride, is one of the most common salts and is obtained from the sea or underground mines. Another curiosity is that different salts have specific uses in industry, such as calcium sulfate, which is used to make chalk and plaster.

5. Capturing Students' Attention: Finally, the teacher can use an experiment or demonstration to capture the students' attention. An idea is to show the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) to produce sodium chloride (NaCl) and water. This can be done with the help of a projector and molecular models to illustrate the reaction. Another idea is to show how salt can be used to melt ice, using a piece of ice and some salt.

Development (20 - 25 minutes)

1. "Salt Hunt" Activity (10 - 12 minutes): The teacher divides the class into groups of 5 students. Each group receives a set of samples of common substances, such as table salt, sugar, baking soda, lemon juice, vinegar, etc. The objective of the activity is to classify each sample as a salt, an acid, or a base. To do this, students must observe the properties of each substance, such as taste, solubility in water, reaction with acid-base indicators, etc. The teacher should move around the room, guiding the groups and clarifying doubts. At the end of the activity, each group should present their conclusions to the class.

   • Step 1: Divide the class into groups and distribute the substance samples.
   • Step 2: Instruct students on how to observe the properties of the substances to classify them.
   • Step 3: Monitor the groups' work and clarify doubts.
   • Step 4: Each group presents their conclusions to the class.

2. "Building Salt Formulas" Activity (10 - 12 minutes): Still in groups, students receive cards with the symbols of different chemical elements and ions. The teacher presents a series of chemical formulas of salts, and students must use the cards to build the formulas. This activity allows students to practice writing chemical formulas of salts, reinforcing the concept that salts are formed by the bonding between a cation and an anion. The teacher should move around the room, monitoring the groups' work and clarifying doubts.

   • Step 1: Distribute the cards with the symbols of chemical elements and ions.
   • Step 2: Present a series of chemical formulas of salts.
   • Step 3: Groups build the formulas using the cards.
   • Step 4: The teacher monitors the groups' work and clarifies doubts.

3. "Salt in the Kitchen" Activity (5 - 7 minutes): To conclude, the teacher proposes a debate on the use of salts in cooking. Students are encouraged to share their experiences and knowledge about the use of salts in food preparation. The teacher should guide the discussion by asking questions to stimulate critical thinking and reflection, and providing additional information as needed.

   • Step 1: Propose a debate on the use of salts in cooking.
   • Step 2: Guide the discussion by asking questions and providing additional information.
   • Step 3: End the lesson, emphasizing the importance of salts in everyday life and industry.

Return (10 - 12 minutes)

1. Group Discussion (3 - 4 minutes): The teacher should promote a group discussion with all students. Each group will have up to 3 minutes to share their conclusions and solutions to the activities carried out. During this discussion, the teacher should ensure that all doubts are clarified and that all important concepts are reinforced.

   • Step 1: Gather all groups for a group discussion.
   • Step 2: Each group shares their conclusions and solutions.
   • Step 3: The teacher clarifies doubts and reinforces important concepts.

2. Connection to Theory (2 - 3 minutes): The teacher should then connect the activities carried out with the theory presented at the beginning of the lesson. This can be done by highlighting the importance of salts and how they are formed from the reaction between acids and bases. The teacher can also review the naming rules for salts and how to write their chemical formulas.

   • Step 1: Connect the activities with the theory presented.
   • Step 2: Review the naming rules for salts and how to write their chemical formulas.

3. Individual Reflection (3 - 4 minutes): Finally, the teacher should propose that students reflect individually on what they learned in the lesson. For this, the teacher can ask the following questions:

   1. What was the most important concept you learned today?
   2. What questions have not been answered yet?
   3. How can you apply what you learned today in everyday situations?

   Students should have a minute to think about each question. Then, they can share their answers with the class, if they wish. The teacher should encourage students to reflect honestly and express any doubts or difficulties they may have.

   • Step 1: Propose that students reflect individually on what they learned.
   • Step 2: Ask the questions and give students a minute to think about each one.
   • Step 3: Students share their answers, if they wish.
   • Step 4: End the lesson, reinforcing the most important concepts and encouraging students to continue studying the subject.

This Return is a crucial stage of the lesson, as it allows the teacher to assess students' understanding of the topic and identify any areas that may need reinforcement in future lessons.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes): The teacher should start the Conclusion by reviewing the main points discussed during the lesson. This includes the definition of salt, the difference between neutral, acidic, and basic salts, the formation of a salt from the reaction between a cation and an anion, the nomenclature of salts, and the writing of their chemical formulas. The teacher can do this through a quick review or a quick quiz to ensure that the concepts were understood.

2. Theory-Practice Connection (1 - 2 minutes): Next, the teacher should emphasize how today's lesson connected theory to practice. This can be done by referring to the activities carried out, such as the "Salt Hunt" and the "Building Salt Formulas", and how they allowed students to apply theoretical concepts in a practical way. The teacher should also mention how the debate on the use of salts in cooking helped contextualize the subject and show its relevance in daily life.

3. Additional Materials (1 minute): The teacher should then suggest some additional study materials for students who wish to deepen their knowledge on the subject. This may include chemistry books, chemistry websites, educational videos online, and chemistry apps. The teacher can also suggest some practical activities for students to do at home, such as observing the properties of different salts in the kitchen or trying to name and write formulas of salts from food labels or cleaning products.

4. Importance of the Subject (1 - 2 minutes): Finally, the teacher should emphasize the importance of salts in everyday life and industry. It should be emphasized that salts are essential for various biological functions, widely used in industry and agriculture, and present in various products we use daily, such as food and cleaning products. The teacher can end the lesson by reaffirming the relevance of the subject and encouraging students to continue exploring the world of chemistry.