Objectives (5 - 7 minutes)

1. Understand the basic structure and characteristics of atoms: Students should be able to describe the basic structure of atoms, including the nucleus (composed of protons and neutrons) and the electron cloud (composed of electrons). They should also understand the characteristics of atoms, such as atomic number, mass number, and electronic configuration.

2. Differentiate between atoms and ions: Students should learn the difference between atoms and ions, understanding that atoms are neutral particles, while ions are charged particles due to the gain or loss of electrons.

3. Identify and describe the formation of ions: Students should be able to identify and describe the process of ion formation, including the loss or gain of electrons and the change in the atom's charge.

Secondary Objectives:

• Apply knowledge in practical situations: Students should be able to apply the knowledge acquired about atoms and ions in practical situations, such as understanding chemical reactions and the formation of ionic compounds.

• Stimulate critical thinking and problem-solving: Through exercises and activities, students should be encouraged to develop critical thinking and problem-solving skills by applying the concepts learned.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher will start the lesson by reviewing the concepts about atomic structure already studied by the students, such as the existence of subatomic particles (protons, neutrons, and electrons), their location in the atom (protons and neutrons in the nucleus and electrons in the electron cloud), and their electric charges. This will serve as a basis for the introduction of the new content. (3 - 5 minutes)

2. Problem situation: The teacher will present two problem situations that will lead students to reflect on the content that will be covered. The first situation will involve the formation of positive and negative ions and how this affects the atom's charge and stability. The second situation will involve the formation of an ionic compound, where students will have to think about which atoms would lose or gain electrons to form the compound. (3 - 5 minutes)

3. Contextualization of the importance of the subject: The teacher will explain how understanding atoms and ions is fundamental to the comprehension of various chemical phenomena in everyday life. It will be highlighted how the formation of ions is present in processes such as the conduction of electricity in solutions and the formation of ionic compounds, which are the basis of many materials and substances present in our daily lives. (2 - 3 minutes)

4. Introduction to the topic: To capture the students' attention, the teacher may share some curiosities about atoms and ions. For example, the discovery that atoms are mainly empty space, with their subatomic particles orbiting at a great distance from the nucleus. Another curiosity is the existence of ions in our body, which play vital roles in biological processes, such as the transmission of nerve impulses. (2 - 3 minutes)

With these steps, the teacher will have prepared the ground for the Introduction of the content in an engaging and meaningful way for the students.

Development (20 - 25 minutes)

1. Theory - Atomic Structure (8 - 10 minutes):

   1.1. Protons, neutrons, and electrons: The teacher begins the explanation by reinforcing the concepts of protons, neutrons, and electrons, and their location in the atom (protons and neutrons in the nucleus and electrons in the electron cloud). It is important to emphasize the electric charges of each of these particles: protons (+1), electrons (-1), and neutrons (neutral).

   1.2. Atomic number and mass number: Next, the teacher introduces the concept of atomic number (represents the quantity of protons in the nucleus) and mass number (sum of the number of protons and neutrons). It is important to highlight that the atomic number determines the chemical element, while the mass number can vary, giving rise to isotopes.

   1.3. Electronic configuration: Finally, the teacher explains the electronic configuration, which describes the distribution of electrons in the different energy levels and sublevels. Linus Pauling's diagram can be used to illustrate this concept.

2. Theory - Atoms and Ions (7 - 8 minutes):

   2.1. Neutral atom: The teacher begins the explanation about atoms and ions by talking about neutral atoms, which have the same number of protons and electrons, resulting in a total charge equal to zero.

   2.2. Ions: Next, the teacher introduces ions, explaining that they are atoms that have gained or lost electrons, resulting in a total charge different from zero. Positive ions (cations) are formed when an atom loses electrons, while negative ions (anions) are formed when an atom gains electrons.

   2.3. Octet rule: The teacher mentions the octet rule, which states that atoms tend to gain, lose, or share electrons to acquire a stable electronic configuration, similar to that of a noble gas (with 8 electrons in the valence shell, except for hydrogen and helium, which have 2 electrons).

3. Practice - Examples and Exercises (5 - 7 minutes):

   3.1. Practical examples: The teacher presents some practical examples to reinforce the theory, such as the formation of the sodium cation (Na+) and the chlorine anion (Cl-), which together form table salt (NaCl).

   3.2. Review exercises: The teacher proposes some review exercises for students to apply what they have learned. For example, asking students to identify the atomic number, mass number, and charge of an atom that has lost 2 electrons.

4. Review and Clarification of Doubts (2 - 3 minutes): The teacher concludes the Development of the lesson by briefly reviewing the main points covered and clarifying any doubts that students may have. It is important to encourage students to ask questions and share their difficulties so that the teacher can adjust the lesson according to the class's needs.

Return (8 - 10 minutes)

1. Connection to the real world (3 - 4 minutes): The teacher should encourage students to reflect on how the learned content can be applied in the real world. Some examples that can be addressed include:

   1.1. Formation of ionic compounds: The teacher can discuss how the formation of ions is essential for the formation of ionic compounds, which are widely found in nature and industry. For example, table salt (NaCl) and calcium carbonate (CaCO3) are common examples of ionic compounds.

   1.2. Conduction of electricity in solutions: The teacher can explain how the presence of ions in a solution allows it to conduct electricity. This can be exemplified by the conductivity of pure water (low) and saltwater (high) or lemon juice (low) and orange juice (high).

   1.3. Biological processes: The teacher can cite examples of biological processes that depend on the presence of ions, such as the transmission of nerve impulses, muscle contraction, and nutrient absorption by plants.

2. Reflection on the lesson (2 - 3 minutes): The teacher should propose that students reflect on what they learned during the lesson. Some questions that can be asked include:

   2.1. What was the most important concept learned today?

   2.2. What questions have not been answered yet?

   2.3. How can you apply what you learned today in your daily life or in other subjects?

3. Group discussion (2 - 3 minutes): To conclude the lesson, the teacher can divide the class into small groups and propose a discussion on the points raised during the reflection. Each group can present their ideas and conclusions to the class, promoting interaction and knowledge exchange among students.

4. Teacher's feedback (1 minute): The teacher should take this opportunity to provide general feedback on the lesson, highlighting strengths and areas that may need more practice or study. The teacher can also reinforce the importance of the content learned for the Chemistry discipline and the students' daily lives.

Conclusion (5 - 7 minutes)

1. Content Summary (2 - 3 minutes):

   1.1. The teacher should recap the main points covered during the lesson, recalling the basic structure of atoms (nucleus with protons and neutrons, and electron cloud with electrons), the difference between atoms and ions (atoms are neutral, ions have a charge due to the loss or gain of electrons), and the formation of ions (loss or gain of electrons, following the octet rule).

   1.2. The teacher should also reinforce the importance of knowledge about atoms and ions for the understanding of various chemical phenomena, from the formation of ionic compounds to the conduction of electricity in solutions.

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

   2.1. The teacher should highlight how the lesson connected theory - through the explanation of concepts and presentation of examples - with practice - through the completion of review exercises.

   2.2. Additionally, the teacher should reiterate the practical applications of the content, such as the formation of ionic compounds and the conduction of electricity in solutions, which were discussed during the lesson.

3. Extra Materials (1 minute):

   3.1. The teacher should suggest some extra materials for students who wish to deepen their understanding of the subject. This may include reference books, educational websites, explanatory videos, and interactive games about atoms and ions.

   3.2. Additionally, the teacher can recommend the completion of additional exercises to practice the content, both from textbooks and digital platforms for teaching chemistry.

4. Importance of the Subject (1 - 2 minutes):

   4.1. To conclude the lesson, the teacher should emphasize the importance of the content learned for the students' daily lives. This can be done by reiterating the practical applications of knowledge about atoms and ions, such as the formation of ionic compounds and the conduction of electricity in solutions.

   4.2. Additionally, the teacher can highlight how understanding atoms and ions is fundamental for the study of other chemistry topics, such as the periodic table, chemical bonds, and chemical reactions.